Title of Invention

A SERINE PROTEASE INHIBITORS

Abstract Compounds of formula (I) in which R2, X, Y, Cy, L and Lp(D)n have the meanings given in the specification, are inhibitors of the serine protease, Factor Xa and pharmaceutical composition thereof are useful in the treatment of cardiovascular disorders.
Full Text Field of invention
This invention relates to a substituted piperazine compounds which are inhibitors
of serine proteases and to pharmaceutical compositions thereof and. their use in the
treatment of the human or animal body.
Background of invention
The serine proteases are a group of proteolytic enzymes which have a common
catalytic mechanism characterized by a particularly reactive Ser residue. Examples of
serine proteases include trypsin, tryptase, chymotrypsin, elastase, thrombin, plasmin,
kallikrein, Complement Cl, acrosomal protease, lysosomal protease, cocoonase, a-lytic
protease, protease A, protease B, serine carboxypeptidase II, subtilisin, urokinase, Factor
VIla, Factor IXa, and Factor Xa.
The serine proteases have been investigated extensively over a period of several
decades and the therapeutic value of inhibitors of serine proteases is well understood.
Serine protease inhibitors play a central role in the regulation of a wide variety of
physiological process including coagulation, fibrinolysis, fertilization, development,
malignancy, neuromuscular patterning and inflammation. It is well known that these
compounds inhibit a variety of circulating proteases as well as proteases that are activated
or released in tissue. It is also becoming clear that serine protease inhibitors inhibit
critical cellular processes, such as adhesion, migration, free radical production and
apoptosis. In addition, animal experiments indicate that intravenously administered serine
protease inhibitors, variants or cells expressing serine protease inhibitors, provide a
protective effect against tissue damage.
Serine protease inhibitors have also been predicted to have potential beneficial
uses in the treatment of disease in a wide variety of clinical areas such as oncology,
neurology, haematology, pulmonary medicine, immunology, inflammation and infectious
disease.
In particular serine protease inhibitors may be
beneficial in the treatment of thrombotic diseases, asthma,
emphysema, cirrhosis, arthritis, carcinoma, melanoma,
restenosis, atheroma, trauma, shock and reperfusion injury.
Thus for example an inhibitor of Factor Xa has value as a
therapeutic agent as an anticoagulant, e.g. in the treatment
and prevention of thrombotic disorders. The use of a Factor Xa
inhibitor as an anticoagulant is desirable in view of the
selectivity of its effect. Many clinically approved
anticoagulants have been associated with adverse events owing
to the non-specific nature of their effects on the coagulation
cascade.
Also, there are well-known associations of al protease
inhibitor deficiency with emphysema and cirrhosis and Cl
esterase inhibitor deficiency with angioedema.
It has now been found that certain aromatic compounds
carrying bulky lipophilic side chains are particularly
effective as inhibitors of serine proteases, especially
proteases with negatively charged P1 specificity pockets, and
most especially the serine proteases thrombin, and most
importantly Factor Xa. The Factor Xa inhibitors of this
invention are potentially useful for the prophylaxis or
treatment of thrombotic disorders such as amongst others
venous thrombosis, pulmonary embolism, arterial thrombosis,
myocardial ischaemia, myocardial infarction, and cerebral
thrombosis. They potentially have benefit in the treatment of
acute vessel closure associated with thrombolytic therapy and
restenosis, e.g. after transluminal coronary angioplasty or
bypass grafting of the coronary or peripheral arteries and in
the maintenance of vascular access patency in long term
hemodialysis patients.
Factor Xa inhibitors of this invention may, with benefit,
form part of a combination therapy with an anticoagulant with
a different mode of action or with a thrombolytic agent.
It has been reported in W099/11658 and W099/11657 that certain benzamidine
and aminoisoquinoline derivatives carrying a bulky lipophilic side chain are excellent
inhibitors of serine proteases. Unfortunately, it has since been found that benzamidine
compounds of WO 99/11658 in general demonstrate poor oral bioavailability.
Surprisingly, it has now been found that certain other aromatic compounds also
show inhibitory activity against serine proteases, in particular Factor Xa, despite the lack
of the amidino or 1-aminoisoquinoline functionality previously believed to be crucial for
activity as a factor Xa inhibitor. Many of these compounds also possess other structural
features that further distinguish them from the compounds of W099/11658 and
W099/11657.
Where compounds of the invention have been tested, they have generally
demonstrated superior oral bioavailability in comparison with benzamidines disclosed in
WO 99/11658. Also, it has been found that the compounds of the invention perform
excellently in the prothrombin time assay (PT) when compared to aminoisoquinolines of
similar factor Xa activity and structure. The PT assay is a coagulation assay and it is
widely accepted that direct acting Factor Xa inhibitors which perform well in the PT
assay are more likely to be good antithrombotics.
In W099/09053 certain 2-aminobenzamide compounds are disclosed as potential
motilin receptor antagonists and in US 3268513 similar 2-aminobenzamide compounds
are suggested as potential antibacterial agents. However, the novel compounds of the
present invention have not before been suggested as potential serine protease inhibitors.
Statement of invention
The present invention relates to a substituted piperazine compound of formula (I)

wherein:
R2 represents:
(i) phenyl optionally being substituted in the 3 and/or
4 position by halo, nitro, thiol, haloalkoxy, hydrazido,
alkylhydrazido, amino, cyano, haloalkyl, alkylthio, alkenyl,
alkynyl, acylamino, tri or difluoromethoxy, carboxy, acyloxy,
MeSO2- or R1, and optionally substituted at the 6 position by
amino, hydroxy, halo, alkyl, carboxy, alkoxycarbonyl, cyano,
amido, aminoalkyl, alkoxy or alkylthio;
(ii) naphth-2-yl optionally substituted at the 6 or 7
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1j and optionally
substituted at the 3 position by amino, hydroxy, halo, alkyl,
carboxy, cyano, amido, aminoalkyl, alkoxy or alkylthio;
(iii) isoquinolin-7-yl, indol-5-yl, indol-6-yl, indazol-
5-yl, indazol-6-yl, benzothiazol-6-yl or benzisoxazol-5-yl
optionally substituted at the 3 position by halo, haloalkoxy,
haloalkyl, cyano, nitro, amino, hydrazido, alkylthio, alkenyl,
alkynyl or R1j;
(iv) benzimidazoi-5-yl or benzothiazol-6-yl optionally
substituted at the 2 position by amino;
(v) thien-2-yl or thien-3-yl optionally substituted at
the 4 or 5 position by halo, haloalkoxy, haloalkyl, cyano,
nitro, amino, hydrazido, alkylthio, alkenyl, alkynyl or R1;
(vi) 3, 4-methylenedioxyphenyl, 2, 3 -dihydroindol -6-yl,
3,3-dichloro-2-oxo-indol-6-yl or 1-methyl-3-aminoindazol-5-yl:
(vii) benzothiazol-2-yl, imidazo[1,2-a]pyrimidin-2-yl or
tetrahydroimidazo[1,2-a]pyrimidin-2-yl;
(viii) pyrazol-2-yl optionally substituted at the 5
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(ix) pyrid-2-yl optionally substituted at the 5 position
by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(x) pyrid-3-yl optionally substituted at the 6 position
by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(xi) benzofur-2-yl optionally substituted at the 3
position by amino, hydroxy, halo, alkyl, carboxy, cyano,
amido, aminoalkyl, alkoxy or alkylthio and at the 5 or 6
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1j;
(xii) indol-2-yl optionally substituted on the indole
nitrogen atom by alkyl and optionally substituted at the 5 or
6 position by halo, haloalkoxy, haloalkyl, cyano, nitro,
amino, hydrazido, alkylthio, alkenyl, alkynyl or R1j;
(xiii) indol-6-yl substituted at the 5 position by amino,
hydroxy, halo, alkyl, carboxy, alkoxycarbonyl, cyano, amido,
aminoalkyl, alkoxy or alkylthio and optionally substituted at
the 3 position by halo, haloalkoxy, haloalkyl, cyano, nitro,
amino, hydrazido, alkylthio, alkenyl, alkynyl or R1j; or
(xiv) benzo[b]thiophen-2-yl optionally substituted at the
3 position by amino, hydroxy, halo, alkyl, carboxy, cyano,
amido, aminoalkyl, alkoxy or alkylthio and at the 5 or 6
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1j; with the
proviso that R2 cannot be aminoisoquinolyl;
R1 represents hydrogen, hydroxy, alkoxy, alkyl,
alkylaminoalkyl, alkanoyl, hydroxyalkyl, alkoxyalkyl,
alkoxycarbonyl, alkylaminocarbonyl, alkylamino, carboxy1,
carboxymethyl, amido or amidomethyl;
R1j represents hydrogen, hydroxy, alkoxy, alkyl,
alkanoyl, hydroxyalkyl, alkoxyalkyl, alkoxycarbonyl,
alkylamino, carboxyl, carboxymethyl, amido or amidomethyl;
-X-X- is -CONH-;
Y (the a-atom) is CH;
Cy represents an optionally R3a substituted: phenyl,
pyridyl, thienyl, thiazolyl, naphthyl, piperidinyl, furanyl,
pyrrolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxazolyl,
imidazolyl, 1,2,4-thiadiazolyl, 1,3,4-thiadiazolyl,
pyrimidinyl, pyridazinyl, quinolyl, isoquinolyl, benzofuryl,
benzothienyl or cycloalkyl group, or a phenyl group
substituted by R3iXi in which Xi is a bond, O, NH or CH2 and
R3i is phenyl, pyridyl or pyrimidyl group optionally
substituted by R3a;
each R3a independently represents hydrogen; hydroxyl;
alkoxy; aralkyloxy; alkyl; alkylaminoalkyl; hydroxymethyl;
carboxy; alkoxyalkyl; alkoxycarbonyl; alkylaminocarbonyl;
aminomethyl; CONH2; CH2CONH2; (1-6C)alkanoylamino;
alkoxycarbonyl ami no; atnino; halo; cyano; nitro; thiol ;
alkylthio; alkylsulphonyl; alkylsulphenyl; alkylsulphonamido;
alkylaminosulphonyl; aminosulphonyl; haloalkoxy; haloalkyl; a
group of the formula -C (X3) N(R11)R12 (wherein X3 is 0 or S and
R11 and R12 are independently selected from hydrogen, methyl,
ethyl, or together with the nitrogen atom to which they are
attached form a pyrrolidin-1-yl, piperidin-1-yl or morpholino
group; or
-OCH2O- which is bonded to two adjacent ring atoms in Cy; and
-L-Lp(D)n is of the formula:

in which Rr is -(CH2)c-Rc -CHReRf, -CH2-CHReRf,
-CH2-CH2-CHReRf, or Rg in which c is 1 or 2; Rc is thienyl,
thiazolyl(which may bear an amino substituent), isothiazolyl,
oxazolyl, isoxazolyl, pyrazolyl, imidazolyl, pyridyl (which
may bear an alkylsulphonyl, aminosulphonyl,
alkylaminosulphonyl, alkylaminocarbonyl, amino, amido, (1-
4C)alkoxycarbonyl, carboxy, acetylamino, chloro, fluoro,
cyano, (l-3C)alkyl, trifluoromethyl, methoxy, ethoxy, nitro,
hydroxy, alkylsulphonylamino, triazolyl or tetrazolyl
substituent), pyrimidinyl, pyridazinyl, pyrazinyl or phenyl
(which may bear a methyl, methylamino, dimethylarnino, carboxy,
dialkylaminosulphonyl, alkylsulphonyl, aminosulphonyl,
alkylaminosulphonyl, alkylatninocarbonyl, amino, amido,
alkoxycarbonyl, acetylamino, chloro, fluoro, cya.no, methoxy,
ethoxy, nitro, hydroxy, alkylsulphonylamino, triazolyl or
tetrazolyl substituent); each of Re and Rf independently is
hydrogen or C1-3alkyl; or CHReRf is cyclopentyl (which may
bear a hydroxy, amino, (1-3C)alkoxy, (1-3C)hydroxyalkyl, (1-
3C)alkyl, carboxy, methoxycarbonyl or ethoxycarbonyl
substituent at the 3- or 4-position), cyclohexyl (which may
bear a hydroxy, amino, (1-3C)alkoxy, (1-3C)hydroxyalkyl, (1-
3C)alkyl, carboxy, methoxycarbonyl or ethoxycarbonyl
substituent at the 3- or 4-position), tetrahydropyran-4-yl,
tetrahydrothiopyran-4-yl, pyrrolidin-3-yl (which may bear a
hydroxy, amino, (1-3C)alkoxy, (1-3C)hydroxyalkyl, (l-3C)alkyl,
carboxy, methoxycarbonyl or ethoxycarbonyl substituent at the
1-position), piperidin-4-yl (which may bear a hydroxy, amino,
(1-3C)alkoxy, (1-3C)hydroxyalkyl, (l-3C)alkyl, carboxy,
i
methoxycarbonyl or ethoxycarbonyl substituent at the 1-
position), or indan-2-yl; and Rg is 2-methylsulphonylphenyl
which may bear a 4-fluoro substituent or Rg is ?6-l,l-
di oxobenzo[b]thiophen-7-yl;
or a physiologically-tolerable salt thereof;
provided that Lp(D)n is not of the formula (K):

wherein X2 is fluoro or hydrogen.
Detailed description of the invention
Thus viewed from one aspect of the invention provides a substituted piperazine
compound of formula (I)
wherein:
R2 is a 5 or 6 membered aromatic carbon ring optionally-
interrupted by a nitrogen, oxygen or sulphur ring atom,
optionally being substituted in the 3 and/or 4 position (in
relation to the point of attachment of X-X) by halo, nitro,
thiol, haloalkoxy, hydrazido, alkylhydrazido, amino, cyano,
haloalkyl, alkylthio, alkenyl, alkynyl, acylamino, tri or
difluoromethoxy, carboxy, acyloxy, MeS02- or R1, or the
substituents at the 3 and 4 positions taken together form a
fused ring which is a 5 or 6 membered carbocyclic or
heterocyclic ring optionally substituted by halo, haloalkoxy,
haloalkyl, cyano, nitro, amino, hydrazido, alkylthio, alkenyl,
alkynyl or R1j, and optionally substituted in the position
alpha to the X-X group (i.e. 6 position for a six membered
aromatic ring etc) by amino, hydroxy, halo, alkyl, carboxy,
alkoxycarbonyl, cyano, amido, aminoalkyl, alkoxy or alkylthio
with the proviso that R2 cannot be aminoisoquinolyl;
each X independently is a C, N, 0 or S atom or a CO,
CR1a, C(R]1a)2 or NR1a group, at least one X being C, CO, CRn1a
or C(Rla)2;
each R1a independently represents hydrogen or hydroxyl,
alkoxy, alkyl, aminoalkyl, hydroxyalkyl alkoxyalkyl,
alkoxycarbonyl, alkylaminocarbonyl, alkoxycarbonylamino,
acyloxymethoxycarbonyl or alkylamino optionally substituted by
hydroxy, alkylamino, alkoxy, oxo, aryl or cycloalkyl;
Rl is as defined for R1a, provided that R1 is not
unsubstituted aminoalkyl;
Y (the a-atom) is a nitrogen atom or a CR1b group;
Cy is a saturated or unsaturated, mono or poly cyclic,
homo or heterocyclic group, preferably containing 5 to 10 ring
atoms and optionally substituted by groups R3a or R3iXi;
each R3a independently is R1c, amino, halo, cyano, nitro,
thiol, alkylthio, alkylsulphonyl, alkylsulphenyl, triazolyl,
imidazolyl, tetrazolyl, hydrazido, alkylimidazolyl, thiazolyl,
alkylthiazolyl, alkyloxazolyl, oxazolyl, alkylsulphonamido,
alkylaminosulphonyl, aminosulphonyl, haloalkoxy, haloalkyl, a
group of the formula -C(X3)N(R11)R12 (wherein X3 is 0 or S;
and R11 and R12 are independently selected from hydrogen,
methyl or ethyl or together with the nitrogen atom to which
they are attached form a pyrrolidin-1-yl, piperidin-1-yl or
morpholino group), or -OCH2O- which is bonded to two adjacent
ring atoms in Cy;
Xi is a bond, O, NH or CH2;
R3i is phenyl, pyridyl or pyrimidinyl optionally
substituted by R3a;
Rlb, Rlc and R1j are as defined for R1a; and
-L-Lp(D)n is of the formula:

in which Rr is -(CH2)C-RC, -CHReRf, -CH2-CHReRf,
-CH2-CH2-CHReRf, or Rg in which c is 1 or 2; Rc is thienyl,
thiazolyl (which may bear an amino substituent), isothiazolyl,
oxazolyl, isoxazolyl, pyrazolyl, imidazolyl, pyridyl (which
may bear in alkylsulphonyl, aminosulphonyl,
alkylaminpsulphonyl, alkylaminocarbonyl, amino, amido, (1-
4C)alkoxycarbonyl, carboxy, acetylamino, chloro, fluoro,
cyano, (l-3C)alkyl, trifluoromethyl, methoxy, ethoxy, nitro,
hydroxy, flkylsulphonylamino, triazolyl or tetrazolyl
substituent), pyrimidinyl, pyridazinyl, pyrazinyl or phenyl
(which may bear a methyl, methylamino, dimethylamino, carboxy,
dialkylaminosulphonyl, alkylsulphonyl, aminosulphonyl,
alkylamix osulphonyl, alkylaminocarbonyl, amino, amido,
alkoxycarbonyl, acetylamino, chloro, fluoro, cyano, methoxy,
ethoxy, nitro, hydroxy, alkylsulphonylamino, triazolyl or
tetrazolyl substituent); each of Re and Rf independently is
hydrogen or C1-3alkyl; or CHReRf is cyclopentyl (which may
bear a hydroxy, amino, (1-3C)alkoxy, (1-3C)hydroxyalkyl, (l-
3C)alkyl, carboxy, methoxycarbonyl or ethoxycarbonyl
substituent at the 3- or 4-position), cyclohexyl (which may
bear a h}droxy, amino, (1-3C)alkoxy, (1-3C)hydroxyalkyl, (1-
3C)alkyl, carboxy, methoxycarbonyl or ethoxycarbonyl
substituent at the 3- or 4-position), tetrahydropyran-4-yl,
tetrahydxothiopyran-4-yl, pyrrolidin-3-yl (which may bear a
hydroxy, amino, (1-3C)alkoxy, (1-3C)hydroxyalkyl, (l-3C)alkyl,
carboxy, methoxycarbonyl or ethoxycarbonyl substituent at the
1-positicn), piperidin-4-yl (which may bear a hydroxy, amino,
(1-3C)alkoxy, (1-3C)hydroxyalkyl, (l-3C)alkyl, carboxy,
methoxycsrbonyl or ethoxycarbonyl substituent at the 1-
position), or indan-2-yl; and Rg is 2-methylsulphonylphenyl
which may bear a 4-fluoro substituent or Rg is ?6-1,1-
dioxobenzo [b]thiophen-7-yl;
or a physiologically-tolerable salt thereof (e.g. a
halide, pjhosphate or sulfate salt or a salt with ammonium or
an organip amine such as ethylamine or meglumine);
provided that Lp(D)n is not of the formula (K):

wherein X2 is fluoro or hydrogen.
In another aspect the invention relates to a serine
protease inhibitor compound of formula (I)
wherein:
R2 is a 5 or 6 membered aromatic carbon ring optionally
interrupted by a nitrogen, oxygen or sulphur ring atom,
optionally being substituted in the 3 and/or 4 position (in
relation to the point of attachment of X-X) by halo, nitro,
thiol, haloalkoxy, hydrazido, alkylhydrazido, amino, cyano,
haloalkyl, alkylthio, alkenyl, alkynyl, acylamino, tri or
difluoromethoxy, carboxy, acyloxy, MeSO2- or R1, or the
substituents at the 3 and 4 positions taken together form a
fused ring which is a 5 or 6 membered carbocyclic or
heterocyclic ring optionally substituted by halo, haloalkoxy,
haloalkyl, cyano, nitro, amino, hydrazido, alkylthio, alkenyl,
alkynyl or R1j, and optionally substituted in the position
alpha to the X-X group (i.e. 6 position for a six membered
aromatic ring etc) by amino, hydroxy, halo, alkyl, carboxy,
alkoxycarbonyl, cyano, amido, aminoaikyl, alkoxy or alkylthio
with the proviso that R2 cannot be aminoisoquinolyl;
each X independently is a C, N, 0 or S atom or a CO,
CRla, C(R1a)2 or NRla group, at least one X being C, CO, CR1a
or C(R1a)2;
each R1a independently represents hydrogen or hydroxyl,
alkoxy,alkyl, aminoaikyl, hydroxyalkyl alkoxyalkyl,
alkoxycarbonyl, alkylaminocarbonyl, alkoxycarbonylamino,
acyloxymethoxycarbonyl or alkylamino optionally substituted by
hydroxy, alkylamino, alkoxy, oxo, aryi or cycloalkyl;
Rl is as defined for R1a, provided that R1 is not
unsubstituted aminoaikyl;
Y (the a-atom) is a nitrogen atom or a CR1b group;
Cy is a saturated or unsaturated, mono or poly cyclic,
homo or heterocyclic group, preferably containing 5 to 10 ring
atoms anjd optionally substituted by groups R3a or phenyl
optionally substituted by R3a;
each R3a independently is R1c, amino, halo, cyano, nitro,
thiol, aLkylthio, alkylsulphonyl, alkylsulphenyl, triazolyl,
imidazolyl, tetrazolyl, hydrazido, alkyl imidazolyl,
thiazolyl, alkyl thiazolyl, alkyl oxazolyl, oxazolyl,
alkylsul phonamido, alkylaminosulphonyl, aminosulphonyl,
haloalkoxy and haloalkyl;
Rlb, Rlc and Rlj are as defined for R1a;
and -L-Lp(D)n is of the formula:

in which Rr is -(CH2)C-Rc -CHReRf, -CH2-CHReRf, or Rg in
which c Ls 1 or 2; Rc is pyridyl or phenyl (which phenyl may
bear a fLuoro, chloro, methyl, CONH2, SO2NH2,
methylaminosulphonyl, dimethylaminosulphonyl, methoxy or
methylsulfonyl substituent); each of Re and Rf independently
is hydrogen or C1-3alkyl; or CHReRf is cyclopentyl (which may
bear a methyl, ethyl or hydroxymethyl substituent at the 3- or
4-position) , cyclohexyl (which may bear a methyl, ethyl or
hydroxymfethyl substituent at the 3- or 4-position),
tetrahyd:ropyran-4-yl, tetrahydrothiopyran-4-yl, pyrrolidin-3-
yl (which may bear a 1-methyl substituent) , piperidin-4-yl
(which may bear a 1-methyl substituent), or indan-2-yl; and Rg
is 2-metkylsulphonylphenyl which may bear a 4-fluoro
substituent or Rg is ?6-l, 1-dioxobenzo [b] thiophen-7-yl;
or a physiologically-tolerable salt thereof;
provided that Lp(D)n is not of the formula (K):
(K)
wherein X2 is fluoro or hydrogen.
In the compounds of the invention, where the alpha atom
is carbon it preferably has the conformation that would result
from construction from a D-a-aminoacid NH2-CRib(Cy)-COOH where
the NH2 represents part of X-X. Likewise the fourth
substituunt R1b at an alpha carbon is preferably a methyl or
hydroxymethyl group or hydrogen. It will be appreciated that
the compounds of formula (I) may exist in racemic or chiral
form, and that the preferred D-isomer may be administered in a
racemic nixture with the L-isomer, or alone.
In the compounds of the invention, unless otherwise
indicated, aryl groups preferably contain 5 to 10 ring atoms
optionally including 1, 2 or 3 heteroatoms selected from 0, N
and S; alkyl, alkenyl or alkynyl groups or alkylene moieties
preferably contain up to 6 carbons, e.g. C1-6 or C1-3; cyclic
groups preferably have ring sizes of 3 to 8 atoms; and fused
multicyclic groups preferably contain 8 to 16 ring atoms.
Examples of particular values for R1a are: hydrogen,
methyl or ethyl. R1a is preferably a hydrogen atom.
The linker group (X-X) from the R2 group to the alpha
atom is preferably selected from -CH=CH-, -CONH-, -C0NRla-,
-NH-C0-, -NH-CH2-, -CH2-NH-, -CH2O-, -OCH2-, -COO-, -0C=0-
and -CH2CH2-. Preferably, the X moiety nearest to the alpha
atom is an NH or 0 atom, most preferably a NH group. The X
moiety alpha to the aromatic ring is preferably a carbon based
group such as CH2 or CO, preferably CO. Thus a particularly
preferred linker X-X is -CONH-. In an alternative embodiment
the linker is a -OCH2- group.
Examples of particular values for R1b are: hydrogen,
(l-4C)alkyl, such as methyl or hydroxy(1-4C)alkyl, such as
hydroxymethyl. R1b is preferably a hydrogen atom.
The alpha atom (Y) is preferably a CH or C(CH3) group.
Especially the alpha atom (Y) is CH.
Exanples of particular values for -CHReRf in a -CHReRf,
-CH2~CHReRf or -CH2-CH2-CHReRf group are 2-propyl, 3-pentyl,
cyclopentyl, cyclohexyl, 4-methylcyclohexyl, tetrahydrothio-
pyran-4-yl, pyrrolidin-3-yl, l-methylpyrrolidin-3-yl, l-(2-
propyl)pyxrolidin-3-yl, piperidin-4-yl, l-methylpiperidin-4-
yl, 1-(2-propyl)piperidin-4-yl and indan-2-yl.
Wher Rr is of the formula -CKReRf a preferred value for
Rr is l methylpiperidin-4-yl.
Preferably Rr is of the formula -(CH2)c-Rc.
Preferably c is 2.
Preferably -L-Lp(D)n is of the formula:

in wihich Rr is -(CH2)C-RC; in which c is 2; Rc is
thienyl, ithiazolyl (which may bear an amino substituent),
isothiazotlyl, oxazolyl, isoxazolyl, pyrazolyl, imidazolyl,
pyridyl (which may bear an amino, methoxycarbonyl, carboxy,
fluoro, cyano, methyl, methylsulphonyl, aminosulphonyl,
methylaminosulphonyl or dimethylaminosulphonyl or
trifluorotnethyl substituent), pyrimidinyl, pyridazinyl,
pyrazinyl or phenyl (which phenyl may bear a fluoro, chloro,
cyano, methyl, amino, methylsulphonyl, aminosulphonyl,
methylaminosulphonyl, dimethylaminosulphonyl, methylamino,
dimethylanino, carboxy, methoxycarbonyl or methoxy
substituent).
Preferably, Rc is thiazolyl, (which may bear an amino
substituent), pyrazolyl, imidazolyl, pyridyl (which may bear a
methylsulphonyl, aminosulphonyl, methylaminosulphonyl,
dimethylaminosulphonyl, fluoro, cyano, methyl or
trifluorortethyl substituent), pyrimidinyl, pyridazinyl,
pyrazinyl or phenyl (which phenyl may bear a fluoro, chloro,
cyano, meqhyl, amino, methylamino, dimethylamino, carboxy,
methoxycarbonyl, methylsulphonyl, aminosulphonyl,
methylamibosulphonyl, dimethylaminosulphonyl or methoxy
substituerit) .
More preferably, Rc is thiazolyl (which may bear an amino
substituent) , pyrazolyl, imidazolyl, pyridyl (which may bear a
fluoro, cyano, methyl or trifluoromethyl substituent),
pyridazinyl or pyrazinyl.
Yet fnore preferably Re is thiazol-2-yl, 2-aminothiazol-4-
yl, pyrazol-1-yl, pyrazol-4-yl, pyridazin-3-yl, imidazol-1-yl,
imidazol-4-yl, pyrazin-2-yl, pyrid-2-yl, pyrid-3-yl, pyrid-4-
yl, 3-fluoropyrid-4-yl, 2-cyanopyrid-4-yl, 2-methylpyrid-4-yl
or 2-trifluoromethylpyrid-6-yl.
Yet nore preferably, Rc is pyrazolyl, imidazolyl,
pyridyl, Dyridazinyl or pyrazinyl.
Preferably Rc is pyrid-2-yl, pyrid-3-yl or pyrid-4-yl.
Most preferably, L is CO and the lipophilic group -Lp(D)n
is selected from the formulae:
wherein;
m represents 0 or 1;
X0 represents CH or N; and
R3 is as defined for R3a.
Preferably m is 1.
Examples of particular values for R3 are:-
hydrogen;
hydroxyl;
for alkoxy: methoxy or ethoxy;
for alkyl optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: (1-6C)alkyl, such as methyl,
ethyl, prqpyl, 2-propyl, butyl, 2-butyl, t-butyl, pentyl, 2-
pentyl or 3- pentyl, (1-6C) alkylarr.ino (1-6C) alkyl, such as
isopropylaminomethyl, dimethylamino-methyl, diethylaminomethyi
or dimethylaminoethyl, or (1-6C)alkanoyl, such as acetyl;
for hydroxyalkyl optionally substituted by hydroxy,
alkylamincd, alkoxy, oxo, aryl or cycloalkyl: (1-
6C) hydroxyalkyl, such as hydroxymethyl or hydroxyethyl,
carboxy orj carboxy (1-5C) alkyl;
for alkoxyalkyl: methoxymethyl;
for alkoxycarbonyl: methoxycarbonyl or ethoxycarbonyl:
for alkylaminocarbonyl: methylaminocarbonyl or
dimethylaminocarbonyl ;
for amindalkyl optionally substituted by hydroxy, alkylamino,
alkoxy, axo, aryl or cycloalkyl: aminomethyl, aminocarbonyl or
aminocarbonyl(1-5C)alkyl;
for alkylamino optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: methylamino, dimethylamino,
ethylamino, formylamino or acetylamino;
amino;
for halo: fluoro or chloro;
cyano;
nitro;
thiol;
for alkylthio: methylthio;
for alkylsulphonyl: methylsulphonyl, ethylsulphonyl or
isopropylsulphonyl;
for alkyl sulphenyl: methylsulphenyl (CH3SO);
for triazolyl: 1,2,4-triazol-2-yl, 1,2,4-triazol-4-yl or
1,2,3-triazol-4-yl;
for imidatolyl: 1,3-imidazol-l-yl or 1,3-imidazol-4-yl;
for tetra::olyl: tetrazol-1-yl or tetrazol-5-yl ;
for alkyliiulphonamido: methylsulphonamido, ethylsulphonamido
or propylfulphonamido;
for alkylaminosulphonyl: methylaminosulphonyl,
ethylaminosulphonyl or propylaminosulphonyl ;
aminosulphonyl;
for haloalkoxy: trifluoromethoxy; and
for haloalkyl: trifluoromethyl or trichloromethyl.
When IR3 is present as a substituent on an aromatic ring,
it is preferably selected from hydrogen, alkylsulphony1,
aminosulph|onyl, alkylaminosulphonyl, alkylaminocarbonyl,
i
amino, amiJdo, alkoxycarbonyl, acetylamino, chloro, fluoro,
cyano, methoxy, ethoxy, nitro, hydroxy, alkylsulphonylamino,
triazolyl and tetrazolyl.
When R3 is present as a substituent on a saturated ring,
it is preferably selected from hydrogen, hydroxy, amino, (1-
3C)alkoxy|, (1-3C) hydroxyalkyl, (l-3C)alkyl, carboxy,
methoxycarbonyl and ethoxycarbonyl.
For example specific Lp(D)n groups include

wherein Ri is hydrogen or (l-6C)alkyl.
Preferably Ri is hydrogen, methyl or ethyl.
More preferably Ri is hydrogen or methyl.
The cyclic group (Cy) attached to the alpha carbon is
preferably an optionally R3a substituted: phenyl, pyridyl,
thienyl, thiazolyl, naphthyl, piperidinyl, furanyl, pyrrolyl,
isoxazolyl, isothiazolyl, pyrazolyl, oxazolyl, imidazolyl,
1,2,4-thiadiazolyl, 1,3,4-thiadiazolyl, pyrimidinyl,
pyridazinyl, quinolyl, isoquinolyl, benzofuryl, benzothienyl
or cycloalkyl group, or a phenyl group substituted by R3iXi in
which Xi is a bond, O, NH or CH2 and R3i is phenyl, pyridyl or
pyrimidyl group optionally substituted by R3a.
The cyclic group (Cy) attached to the alpha carbon is
more preferably an optionally R3a substituted phenyl, pyridyl
(such as Pyrid-2-yl, pyrid-3-yl or pyrid-4-yl), thienyl (such
as thien-2-yl or thien-3-yl), thiazolyl (such as thiazol-2-yl,
thiazol-4-yl or thiazol-5-yl), naphthyl (such as naphth-1-yl),
piperidinyl (such as piperidin-4-yl) or cycloalkyl, such as a
cyclohexyl group.
Examples of particular values for R3a are: -
hydrogen;
hydroxyl;
for alkoxy optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: alkoxy, such as methoxy or
ethoxy, or aralkyloxy, such as benzyloxy;
for alkyl optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: alkyl, such as methyl or
ethyl, or alkylaminoalkyl, such as methylaminomethyl or
dime thylamfinome thy 1 ;
for hydroxyalkyl optionally substituted by hydroxy,
alkylamino, alkoxy, oxo, aryl or cycloalkyl: hydroxymethyl or
carboxy;
for alkoxyalkyl: methoxymethyl;
for alkoxycarbonyl: methoxycarbonyl or ethoxycarbonyl;
for alkylafiinocarbonyl: methylaminocarbonyl or
dimethylaminocarbonyl;
for aminoalkyl optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: aminomethyl, CONH2 or
CH2CONH2;
for alkylamino optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: (1-6C)aikanoylamino, such as
acetylaminO;
for alkoxycarbonylamino: methoxycarbonylaminno,
ethoxycarbonylamino or t-butoxycarbonylamino;
amino;
for halo: fluoro or chloro;
cyano;
nitro;
thiol;
for alkylthio: methylthio;
for alkylsulphonyl: methylsulphonyl or ethylsulphonyl;
for alkylsulphenyl: methylsulphenyl;
for alkylsulphonamido: methylsulphonylamido or
ethylsulphonylamido;
for alkylaminosulphonyl: methylaminosulphonyl or
ethylaminosulphonyl;
aminosulplonyl;
for haloalLkoxy: trifluoromethoxy;
for haloalkyl: trifluoromethyl;
for a group of the formula -C(X3)N(R11)R12 (wherein X3 is 0 or
S and R11 and R12 are independently selected fronr. hydrogen,
methyl, ethyl, or together with the nitrogen atom to which
they are attached form a pyrrolidin-1-yl, piperidin-1-yl or
morpholino group: -CONH2, -CONHMe, -CON(Me)2, -C(S)NH2,
-C(S)NHMe, -C(S)N(Me)2, pyrrolidin-1-
ylcarbonyfl.piperidin-1-ylcarbonyl or morpholinocarbonyl; and
-OCH2O- which is bonded to two adjacent ring atoms in Cy.
In another aspect R3a is selected from hydrogen,
hydroxyl, alkoxy, alkyl (optionally substituted by hydroxy,
alkylaminb, alkoxy, oxo, aryl or cycloalkyl), hydroxyalkyl
(optionally substituted by hydroxy, alkylamino, alkoxy, oxo,
aryl or qycloalkyl), alkoxyalkyl, alkoxycarbonyl,
alkylaminccarbonyl, alkoxycarbonyiamino, alkylamino
(optionally substituted by hydroxy, alkylamino, alkoxy, oxo,
aryl or cycloalkyl), aminoalkyl (substituted by hydroxy,
alkylamino, alkoxy, oxo, aryl or cycloalkyl), amino, halo,
cyano, nitro, thiol, alkylthio, alkylsulphonyl,
alkylsulphenyl, alkylsulphonamido, alkylaminosulphonyl,
aminosulphonyl, haloalkoxy and haloalkyl.
Preferably X3 is 0.
Examples of more specific values for R3a include
hydrogen, hydroxyl, methoxy, ethoxy, methyl, ethyl,
hydroxymethyl, carboxy, methoxymethyl, methoxycarbonyl,
ethoxycarl onyl, methylaminocarbonyl, dimethylamino-carbonyl,
aminomethyl, CONH2, CH2CONH2, acetylamino,
methoxycarbonylamino, ethoxycarbonylamino, t-
butoxycarlonylamino, amino, fluoro, chloro, bromo, cyano,
nitro, thil, methylthio, methylsulphonyl, ethylsulphonyl,
methylsulj henyl, methylsulphonylamido, ethylsulphonylamido,
methylaminosulphonyl, ethylaminosulphonyl, aminosulphonyl,
trifluoromethoxy, trifluoromethyl, bromo, -OCH2O- (which is
bonded to two adjacent ring atoms in Cy) and -C (X3) N(R11) R12
(wherein X3 is 0 or S and R11 and R12 are independently
selected from hydrogen, methyl or ethyl or together with the
nitrogen atom to which they are attached form a pyrrolidin-1-
yl, piperidin-1-yl or morpholino group).
More examples of specific values for R3a include
hydrogen, hydroxyl, methoxy, ethoxy, methyl, ethyl,
hydroxymethyl, carboxy, methoxymethyl, methoxycarbonyl,
ethoxycarbonyl, methylaminocarbonyl, dimethylamino-carbonyl,
aminomethyl, C0NH2, CH2CONH2, acetylamino,
methoxycarbonylamino, ethoxycarbonylamino, t-
butoxycarbonylamino, amino, fluoro, chloro, cyano, nitro,
thiol, methylthio, methylsulphonyl, ethylsulphonyl,
methylsulphenyl, methylsulphonylamido, ethylsulphonylamido,
methylaminosulphonyl, ethylaminosulphonyl, aminosulphonyl,
trifluoromethoxy and trifluoromethyl.
Preferably R3a is hydrogen, hydroxyl, methoxy, methyl,
amino, fluoro, chloro, ethylsulphonylamino, amido or
methylaminocarbonyl.
Preferably Cy is selected from:
wherein:
X' is selected from O, S and NMe;
X' is selected from O and S;
X'' is selected from O, S, NH and NMe;
Y' is selected from hydrogen, amino and methyl;
RO is selected from hydrogen, methyl, fluoro, chloro,
trifluoromethyl, methoxy, methylthio, methylsulphinyl and
methylsulphonyl;
Rm is selected from hydrogen, methyl, fluoro, chloro,
trifluoromethyl, methoxy, methylthio, methylsulphinyl,
methylsuphonyl, carboxy, methoxycarbonyl and a group of the
formula -C (X3) N(rH) r12 (wherein X3 is 0 or S and R11 and R12
are independently selected from hydrogen, methyl or ethyl or
together with the nitrogen atom to which they are attached
form a pyrrolidin-1-yl, piperidin-1-yl or morpholino group);
Rp is selected from hydrogen and fluoro; or
Ro and Rm or Rm and Rp form an -OCH2O- group; or
Ro and Rm together with the ring to which they are attached
form a 5 or 6 membered aryl or heteroaryl ring (wherein the
heteroary ring contains 1 or 2 heteroatoms selected from
nitrogen, oxygen and sufur);
one of RO1 and RO2 is hydrogen and the other is RO.
More preferably Cy is selected from phenyl (optionally
substituted by methyl, ethyl, prop-2-yl, phenoxy, hydroxy,
ethoxy, benzyloxy, prop-2-yloxy, nitro, amino, acetylamino,
methylsulfonylanrino, dimethylamino, chloro, methoxy,
trifluoromethyl, methylthio, methylsulfonyl, tert-butylthio,
tert-butylsulfonyl, aminosulfonyl or carbamoyl), pyridyl,
thienyl, furanyl, imidazolyl, thiazolyl (optionally
substituted by amino), napththyl, isoquinolinyl and
guinolinyl.
Yet more preferably, Cy is selected from phenyl, 2-
chlorophenyl, 2-methoxyphenyl, 4-carbamoylphenyl, pyrid-2-yl,
pyrid-3-yl, pyrid-4-yl, thien-2-yl, thien-3-yl, furan-2-yl,
furan-3-yl, imidazol-2-yl, thiazol-2-yl, thiazol-4-yl,
thiazol-5-yl, naphthyl, isoquinoiin-5-yl, isoquinolin-8-yl,
quinolin-4-yl, quinolin-5-yl, and quinolin-8-yl.
Other examples of values for Cy are 4-aminophenyl, 4-N-
methylamidophenyl, 4 - (N, N-dimethyl) amidophenyl, 2 -
methylphenyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl,
4-hydroxyphenyl, 4-methoxyphenyl, 4-carboxyphenyl, 3-
ethylsulphonylaminophenyl, 2-methylthiazol-4-yl, 1-
methylpiperidin-4-yl, cyclopentyl, cyclohexyl, naphth-1-yl, 2-
aminothiazol-4-yl, 2-trifluorotnethylphenyl, 3-
methylthiophenyl, 2-methylsulphonylphenyl, 3-bromophenyl, 3-
cyanophenyl and benzo[b]thiophen-3-yl.
Yet more preferably Cy is selected from phenyl, 2-
chlorophenyl, 2-methoxyphenyl, 4-carbamoylphenyl, pyrid-2-yl,
pyrid-4-yl, thien-2-yl, thien-3-yl, furan-2-yl, fupran-3-yl,
imidazol-2-yl, thiazol-2-yl, thiazol-4-yl, thiazol-5-yl and
quinolin-4-yl.
Most preferably, Cy is selected from phenyl, 2-
methoxyphenyl, 4-carbamoylphenyl and pyrid-2-yl.
Most preferably Cy is phenyl.
Examples of particular values for R1c are:
hydrogen;
hydroxyl;
for alkoxy: methoxy or ethoxy;
for alkyl optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: alkyl, such as methyl or
ethyl, or alkylaminoalkyl, such as methylaminomethyl or
dimethylaminomethyl;
for hydroxyalkyl: hydroxymethyl;
for alkoxyalkyl: methoxymethyl;
for alkoxycarbonyl: methoxycabonyl or ethoxycarbonyl;
for alkylaminocarbonyl: methylaminocarbonyl or
dimethylaminocarbonyl;
for alkoxycarbonylamino: methoxycarbonylamino,
ethoxycarbonylamino or t-butoxycarbonylamino;
for alkylamino optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: (1-6C)alkanoylamino, such as
acetylamino; and
for aminoalkyl substituted by hydroxy, alkylamino, alkoxy,
oxo, aryl or cycloalkyl: aminomethyl, CONH2 or CH2CONH2.
Referring to R2, examples of a 5 or 6 membered aromatic
carbon ring optionally interrupted by a nitrogen, oxygen or
sulphur ring atom in R2 are phenyl/ pyrrolyl, such as 2-
pyrrolyl; pyridyl, such as 3-pyridyl; pyrazinyl, such as 2-
pyrazinyl; furyl, such as 2-furyl; and thienyl, such as 2-
thienyl or 3-thienyl. Preferably the ring is interrupted
(i.e. a carbon atom is replaced) by at most one heteroatom.
In another aspect the ring is phenyl, 2-thienyl or 2-pyrrolyl.
In yet another aspect, the ring is phenyl.
When the ring is phenyl, the group R2 may be a group of
formula

in which R5 is amino, hydroxy or hydrogen, and Rg and R7 which
may be the same or different represent halo, nitro, thiol,
cyano, haloalkyl, haloalkoxy, amido, hydrazido, amino,
alkylthio, alkenyl, alkynyl or R1 or taken together form a 5
or 6 membered fused carbocyclic ring or 5 membered
heterocyclic ring, which may itself be substituted by R1j ,
amino, halo, cyano, nitro, thiol, alkylthio, haloalkyl,
haloalkoxy.
When the substituents at the 3 and 4 positions taken
together form a fused ring which is a 5 or 6 membered
carbocyclic or heterocyclic ring, examples of the resultant
bicyclic ring are naphthyl, such as 2-naphthyl;
benzimidazolyl, such as benzimidazol-5-yl or benzimidazol-6-
yl; isoquinolinyl, such as isoguinolin-7-yl; indolyl, such as
indol-2-yl, indol-5-yl or indol-6-yl; indazolyl, such as
indazol-5-yl; indazol-6-yl; 3,4-tnethylenedioxyphenyl;
dihydroindolyl, such as 2,3-dihydroindol-6-yl; benzothiazolyl,
such as benzothiazol-2-yl or benzothiazol-6-yl;
benzo[b]thiophenyl, such as benzo[b]thiophen-2-yl; benzofuryl,
such as benzofur-2-yl; imidazo [1,2-ajpyritnidinyl, such as
imidazo[l,2-a]pyrimidin-2-yl; tetrahydroimidazo[1,2-
a]pyrimidinyl, such as tetrahydroimidazo[1,2-a] pyrimidin-2-yl;
and benzisoxazolyl, such as benzisoxazol-5-yl.
Preferably, R2 is phenyl, thien-2-yl, naphthyl, indol-2-
yl, indol-6-yl, benzo[b]furan-5-yl, benzo[b]thiophen-2-yl or
benzimidazol-2-yl (each of which is optionally substituted as
hereinabove defined).
It is preferred that at least one of Rg and R7 be other
than hydrogen and that Rg, if present, is preferably a
substituent containing one or more polar hydrogens such as
hydroxy, amino, alkylamino, alkylaminoalkyl, aminocarbonyl,
alkylaminocarbonyl, hydrazo and alkylhydrazo; alternatively Rg
and R7 are joined together in the formation of a naphthyl or
indolyl or azaindolyl or diazaindolyl group.
It is especially preferred that Rg be amino and R7 be
chloro, bromo, methyl, methoxy or vinyl; or that Rg and R7
taken together form an indolyl ring with the NH at the 6-
position or taken together form a naphthyl ring.
In another aspect R2 represents:
(i) phenyl optionally being substituted in the 3 and/or
4 position by halo, nitro, thiol, haloalkoxy, hydrazido,
alkylhydrazido, amino, cyano, haloalkyl, alkylthio, alkenyl,
alkynyl, acylamino, tri or difluoromethoxy, carboxy, acyloxy,
MeSC^- or Rj_, and optionally substituted at the 6 position by
amino, hydroxy, halo, alkyl, carboxy, alkoxycarbonyl, cyano,
amido, aminoalkyl, alkoxy or alkylthio;
(ii) naphth-2-yl optionally substituted at the 6 or 7
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or Rxj and optionally
substituted at the 3 position by amino, hydroxy, halo, alkyl,
carboxy, cyano, amido, aminoalkyl, alkoxy or alkylthio;
(iii) isoquinolin-7-yl, indol-5-yl, indol-6-yl, indazol-
5-yl, indazol-6-yl, benzothiazol-6-yl or benzisoxazol-5-yl
optionally substituted at the 3 position by halo, haloalkoxy,
haloalkyl, cyano, nitro, amino, hydrazido, alkylthio, alkenyl,
alkynyl or R1j;
(iv) benzimidazol-5-yl or benzothiazol-6-yl optionally
substituted at the 2 position by amino;
(v) thien-2-yl or thien-3-yl optionally substituted at
the 4 or 5 position by halo, haloalkoxy, haloalkyl, cyano,
nitro, amino, hydrazido, alkylthio, alkenyl, alkynyl or R1;
(vi) 3,4-methylenedioxyphenyl, 2,3-dihydroindol-6-yl,
3,3-dichloro-2-oxo-indol-6-yl or l-methyl-3-aminoindazol-5-yl;
(vii) benzothiazol-2-yl, imidazo[1,2-a]pyrimidin-2-yl or
tetrahydroimidazo[1, 2-a] pyrimidin-2-yl;
(viii) pyrazol-2-yl optionally substituted at the 5
position by halo, haloalkoxy, haloaikyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(ix) pyrid-2-yl optionally substituted at the 5 position
by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(x) pyrid-3-yl optionally substituted at the 6 position
by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(xi) benzofur-2-yl optionally substituted at the 3
position by amino, hydroxy, halo, alkyl, carboxy, cyano,
amido, aminoalkyl, alkoxy or alkylthio and at the 5 or 6
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1j;
(xii) indol-2-yl optionally substituted on the indole
nitrogen atom by alkyl and optionally substituted at the 5 or
6 position by halo, haloalkoxy, haloalkyl, cyano, nitro,
amino, hydrazido, alkylthio, alkenyl, alkynyl or R1j;
(xiii) indol-6-yl substituted at the 5 position by amino,
hydroxy, halo (such as fluoro or chloro), alkyl, carboxy,
alkoxycarbonyl, cyano, amido, aminoalkyl, alkoxy or alkylthio
and optionally substituted at the 3 position by halo (such as
chloro), haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio,palkenyl, alkynyl or R1j; or
(xiv) benzo[b]thiophen-2-yl optionally substituted at the
3 position by amino, hydroxy, halo, alkyl, carboxy, cyano,
amido, aminoalkyl, alkoxy or alkylthio and at the 5 or 6
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or Rij.
Examples of particular values for substituents that may
be present on R2 are:
for halo: fluoro, chloro, bromo or iodo;
nitro;
thiol;
for haloalkoxy: difluoromethoxy or trifluoromethoxy;
hydrazido;
for alkylh'ydrazido: methylhydrazido;
amino ;
cyano;
for haloalkyl: trifluoromethyl;
for alkylthio: methyl thio,-
for alkenyl: vinyl;
for alkynyl: ethynyl;
for acylamino: acetylamino;
carboxy;
for acyloxy: acetoxy;
hydroxy;
for alkyl: methyl or ethyl;
amido (CONH2);
for aminoalkyl: aminomethyl; and
for alkoxy: methoxy or ethoxy.
Preferably R2 is optionally substituted by 1 or 2
substituents selected from fluoro, chloro, amino, methyl,
ethyl and methoxy.
Examples of particular values for R1 are:
hydrogen;
hydroxy;
for alkoxy: methoxy or ethoxy;
for alkyl optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: alkyl, such as methyl or
ethyl, alkylaminoalkyl, such as dimethylaminomethyl, or
alkanoyl, such as acetyl;
for hydroxyalkyl: hydroxymethyl;
for alkoxyalkyl: methoxymethyl;
for alkoxycarbonyl: methoxycarbonyl;
for alkylaminocarbonyl: methylaminocarbonyl ;
for alkylamino: methylamino, ethylamino or dimethylamino;
for hydroxyalkyl substituted by hydroxy, alkylamino, alkoxy,
oxo, aryl or cycloalkyl: carboxyl or carboxymethyl,• and
for aminoalkyl substituted by hydroxy, alkylamino, alkoxy,
oxo, aryl or cycloalkyl: amido (CONH2) or ami dome thy 1.
Examples of particular values for R1j are:
hydrogen;
hydroxy;
for ,alkoxy: methoxy or ethoxy;
for alkyl optionally substituted by hydroxy, alkylamino,
alkoxy, oxo, aryl or cycloalkyl: alkyl, such as methyl or
ethyl, or alkanoyl, such as acetyl;
for hydroxyalkyl: hydroxymethyl;
for alkoxyalkyl: methoxymethyl;
for alkoxycarbonyl: methoxycarbonyl;
for alkylamino: methylamino, ethylamino or dimethylamino;
for hydroxyalkyl substituted by hydroxy, alkylamino, alkoxy,
oxo, aryl or cycloalkyl: carboxyl or carboxymethyl; and
for aminoalkyl substituted by hydroxy, alkylamino, alkoxy,
oxo, aryl or cycloalkyl: amido (CONH2) or amidomethyl.
In yet another aspect R2 represents:
(i) phenyl optionally being substituted in the 3 and/or
4 position by fluoro, chloro, bromo, iodo, nitro,
difluoromethoxy, trifluoromethoxy, amino, cyano,
trifluoromethyl, methylthio, vinyl, carboxy, acetoxy, MeSO2-,
hydroxy, methoxy, ethoxy, methyl, methoxycarbonyl,
methylamino, ethylamino or amido, and optionally substituted
at the 6 position by amino, hydroxy, fluoro, methoxycarbonyl,
cyano or aminomethyl (preferably phenyl substituted in the 4
position by chloro, amino, vinyl, methylamino, methyl or
methoxy, optionally at the 3 position with amino or hydroxy,
and optionally at the 6 position with amino or hydroxy);
(ii) naphth-2-yl optionally substituted at the 6,
position by hydroxy and optionally substituted at the 3
position by amino or hydroxy;
(iii) isoquinolin-7-yl, indol-5-yl, indol-6-yl, indazol-
5-yl, indazol-6-yl, benzothiazol-6-yl or benzisoxazol-5-yl
optionally substituted at the 3 position by chloro, bromo,
amino, methyl or methoxy (preferably indol-6-yl optionally
substituted at the 3 position by chloro, bromo, methyl or
methoxy)/
(iv) benzimidazol-5-yl or benzothiazol-6-yl optionally
substituted at the 2 position by amino;
(v) thien-2-yl or thien-3-yl optionally substituted at
the 4 or 5 position by methylthio, methyl or acetyl;
(vi) 3,4-methylenedioxyphenyl, 2,3-dihydroindol-6-yl,
3 , 3-dichloro-2-oxo-indol-6-yl or l-methyl-3-aminoindazol-5-yl;
(vii) benzothiazol-2-yl, imidazo[1,2-a]pyrimidin-2-yl or
tetrahydroimidazo[1,2-a] pyrimidin-2-yl ;
(viii) pyrazol-2-yl substituted at the 5 position by
methyl;
(ix) pyrid-2-yl optionally substituted at the 6 position
by chloro;
(x) pyrid-3-yl optionally substituted at the 4 position
by chloro;
(xi) benzofur-2-yl optionally substituted at the 3
position by chloro, methyl or methoxy, at the 5 or 6 position
by methyl and at the 6 position by methoxy;
(xii) indol-2-yl optionally substituted on the indole
nitrogen at;om by methyl and optionally substituted at the 5 or
6 position by fLuoro, chloro, bromo, methyl or methoxy;
(xiii) indol-6-yl substituted at the 5 position by
chlorc, fluoro or hydroxy and optionally substituted at the 3
position by chloro or methyl; or
(xiv) benzo[b] thiophen-2-yl optionally substituted at the
3 position by fluoro, chloro or methyl, and optionally
substituted at the 5 or 6 position by fluoro, chloro, methyl,
hydroxy, or metaoxy.
Particular values for R2 are:
(i) phenyl, 2-aminophenyl, 3-aminopheny1, 2-amino-3-
fluorophenyl, 2-amino-4-fluorophenyl, 2-amino-4-chlorophenyl,
2~arp.ino~3-bromcphenyl, 2-amino-3-nitrophenyl, 2-amino-4-
nitrophenyl, 3,4-dimethoxy-5-aminopheny1, 2-amino-4-
methylphenyl, 2 -amino-3-methylphenyl, 2-amino-3-methoxyphenyl,
3,4-diaminophenyl, 3,5-diaminopheny1, 3-amino-4-fluorophenyl,
2 --arrin.o-4-chlorophenyl, 3-amino-4-bromophenyl, 3-amino-4-
hydroxyphenyl, 3-amino-4-carboxymethylphenyl, 3-amino-4-
tnethyiphen.yl, 3 amino-4-methoxyphenyl, 2-fluorophenyl, 4-
f lucro- 7i -cyanop.: enyl, 3-chlorophenyl, 3-chloro-4-hydroxphenyl,
3 -chloro-5-iiydr hydroxyphanyl, -chloro-3 -hydroxyphenyl, 4-chloro-3-
met:.ylpheriyl, 4 chloro-3-methoxyphenyl, 4-bromophenyl, 4-
brcx.:.methylp inyl, 4-iodophenyl, 2-cyanophenyl, 3-
cyanopher;yl, 4-cyanophenyl, 3-cyano-5-aminopheny 1, 2-
hydroxpheryl, 2-aydroxy-4-methoxyphenyl, 3-hydroxphenyl, 3-
hyddroxyl methyl ohenyl, 2,4- dihydroxyphenyl, 3,4-
dihyroyypen 1, 3-hydroxy-4-methoxyphenyl, 4-
difliorccrthoj plenyl, 4-trifluoromethoxphenyl, 4-
trith pi enyl, 4-methyl thiophenyl, 4-
methoxycarbonyl phenyl, 4-acetoxyphenyl, 4-
methanesulfony -penyl, 3-methylphenyl, 3-methyl-5-aminopheny 1,
4-methylpheny 4-vinylphenyl, 4-methoxyphenyl, 4-
ethoxyphenyl, 4-methoxy-3-chlorophenyl, 4-methoxy-3-
methylphenyl, 3-methylaminophenyl, 4-methylaminophenyl, 4-
ethylaminophenyl or 2-aminomethylphenyl;
(ii) naphth-2-yl, 3-aminonaphth-2-yl, 3-hydroxynaphth-2-
yl or 6-hydroxynaphth-2-yl;
(iii) isoquinolin-7-yl, indol-5-yl, indol-6-yl, 3-
chloroindol-6-yl, 3-bromoindol-6-yl, 3-methylindol-6-yl, 3-
methoxyindol-6-yl, indazol-5-yl, 3-aminoindazol-5-yl, indazol-
6-yl, benzothiazol-6-yl, 3-aminobenzisoxazol-5-yl ;
(iv) benzimidazol-5-yl, 2-aminobenzimidazol-5-yl, or
benzothiazol-6-yl;
(v) thien-2-yl, 5-methylthien-2-yl, 5-methylthio-thien-2-
yl, 5-acetylthien-2-yl or thien-3-yl;
(vi) 3,4-methylenedioxyphenyl, 2,3-dihydroindol-6-yl,
3,3-dichloro-2-oxo-indol-6-yl or l-methyl-3-arainoindazol-5-yl;
(vii) benzothiazol-2-yl, imidazo [1, 2-a]pyritnidin-2-yl or
tetrahydroimidazo[l,2-a]pyrimidin-2-yl;
(viii) 5-methylpyrazol-2-yl;
(ix) 5-chloropyrid-2-yl;
(x) pyrid-3-yl, 6-chloropyrid-3-yl;
(xi) benzofur-2-yl, 5-chlorobenzofur-2-yl, 3-
methylbenzofur-2-yl, 5-methylbenzofur-2-yl, 6-methoxybenzofur-
2-yl;
(xii) indol-2-yl, 5-fluoroindol-2-yl, 5-chloroindol-2-yl,
5-methylindol-2-yl, 5-methoxindol-2-yl, 6-methoxyindol-2-yl
and 1-methyl-indol-2-yl;
(xiii) 5-fluoroindol-6-yl; or
(xiv) benzo[b]thiophen-2-yl, 5-chloro- benzo[b]thiophen-
2-yl or 6-chlorobenzo[b] thiophen-2-yl.
Preferably, R2 is selected from one of the formulae (A1)
to (H1):
wherein X4 is 0 or S, R13 is selected from hydrogen,
fluoro [except for (C)] , chloro or methyl and R14 is selecte
from hydrogen, methyl, ethyl, fluoro, chloro, and methoxy an
Rl5 is selected from hydrogen, methyl, fluoro, chloro and
amino.
More preferably, R2 is of the formula (A') (wherein R14
is selected from hydrogen, methyl, ethyl, fluoro, chloro, an
methoxy and R15 is selected from hydrogen, methyl, fluoro,
chloro and amino) or of the formula (B1) (wherein R13 is
chloro) or of the formula (C) (wherein R13 is selected from
hydrogen, methyl and chloro) or of the formula (D') (wherein
Rl3 is selected from hydrogen, methyl, fluoro and chloro) or
of the formula (E1) (wherein R13 is hydrogen) or of the
formula (G1) (wherein R13 is chloro).
Yet more preferably, R2 is 4-chlorophenyl, 4-
methoxyphenyl, 3-amino-4-chlorophenyl, indol-2-yl, 5-
chloroindol-2-yl, indol-6-yl, 3-chloroindol-6-yl or 3-
methylindol-6-yl. Another R2 group of particular interest is
3-aminobenzisoxazol-5-yl.
Yet more preferably, R2 is of the formula (A') or (C')
and R13/R14 and R15 are as defined hereinabove.
Most preferably, R2 is of the formula (A') and R14 is
methoxy and R15 is hydrogen or of the formula (C') and R13 is
hydrogen, methyl or chloro.
Another preferred compound of the present invention is
one of the formula:

wherein Cy and R2 are as herinabove defined.
A preferred compound of the present invention is of the
formula:

wherein Cy, R2 and Rc are as hereinabove defined.
Especial mention may be made of:-
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(4-pyridinyl)-
ethyl]piperazine;
1-(3-Chloroindole-6-carbonyl-D-phenylglycinyl)-
4-[2-(4-pyridinyl)ethyl]piperazine;
1- (4-Methoxybenzoyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
yl)piperazine;
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
yl)piperazine;
1-(4-Methoxybenzoyl-D-(2-chlorophenyl)glycinyl)-4-(l-methyl-
piperidin-4-yl)piperazine;
1-(Indole-6-carbonyl-D-(2-chlorophenyl)glycinyl)-4-(1-methyl-
piperidin-4-yDpiperazine; and
1- (4-Methoxybenzoyl-D- (2-trifluoromethylphenyl) glycinyl)-4-(1-
methylpiperidin-4-yl)piperazine;
and physiologically-tolerable salts thereof.
Compounds in this group have been found to have good oral
exposure and a desirable pharmacological/toxicological
profile.
The compounds of the invention may be prepared by
conventional chemical synthetic routes or by routes as
illustrated by the following examples.
The compounds of the formula (I) may be prepared by
forming the -X-X- bond from appropriate intermediates. For
example, when -X-X- is -CONH- or -CO-NR1a-, by reacting a
compound of the formula (10): H2N-Y-(Cy)-L-Lp(D)n with a
compound of the formula R2-COOH, under conditions known for
the formation of an amide bond. The reaction is conveniently
carried out in the presence of a benzotriazole-based reagent
such as 1-hydroxybenzotriazole or l-hydroxy-7-
azabenzotriazole, in an inert organic solvent such as
dimethylformamide and/or methylene chloride. The reaction
mixture is usually taken to 0°C and then a dehydrating agent
such as dicyclohexylcarbodiimide or 1-(3-dimethylaminopropyl)-
3-ethylcarbodiimide added. Other suitable reagents and
solvents are known in the art, for example an acid halide,
such as R2-COCI.
Compounds wherein -X-X- is -NHCO- or -NHCH2- may be
formed from the appropriate intermediates using reaction
conditions for the formation of an amide bond as described
above and if necessary subsequent reduction of the resulting
amide bond.
Compounds of the formula (I) wherein -X-X- is of the
formula -CH2NH- may be prepared by reducing the corresponding
compound of the formula (I) wherein -X-X- is -CONH- or by
reaction of a compound of formula (10): H2N-Y-(Cy)-L-Lp(D)n
with a compound of the formula R2CHO and reducing the
intermediate of the formula (I) wherein -X-X- is -C=N- with,
for example, sodium cyanoborohydride.
When -X-X- is -CH=CH-, the compounds of the formula (I)
may be prepared using the Wittig or Horner-Emmons reactions.
The corresponding compound in which -X-X- is -CH2CH2- can be
formed by reduction of the -CH=CH- group, for example with
hydrogen over a palladium-on-carbon catalyst.
An -X-X- bond of the formula -COO- or -OC(O)- may be
formed by reacting the appropriate hydroxy and activated
carboxylic acid (e.g. acid chloride or reactive ester)
intermediates under conditions known for ester bond formation.
Alternatively, a hydroxy and a carboxylic acid intermediate
could be reacted together in the presence of
diethylazodicarboxylate/triphenylphosphine.
An -X-X- bond of the formula -CH2O- or -OCH2- may be
formed by reacting the appropriate hydroxy intermediate with
the appropriate alkyl halide in the presence of a base.
Conditions for the formation of an ether bond are known in the
art.
These reactions can also be used to form intermediates,
which contain one of the above -X-X- bonds.
Compounds of the formula (I) in which Rr is -(CH2)c-Rc
may also be prepared by reductive coupling a compound of the
formula (11):
with a compound of formula (12)
OHC-(CH2)c-l-RC
The reaction is conveniently performed in the presence of
a reducing agent, such as sodium cyanobrohydride. Convenient
solvents include alcohols, such as methanol, optionally with a
halogenated hydrocarbon as solvent, such as 1,2-
dichloroethane, and acetic acid. The coupling is conveniently
effected at a temperature in the range of from 0 to 100°C.
The intermediates of formula (11) are believed to be
novel, and are provided as a further aspect of the invention.
The intermediates of formula (11) in which X-X is CONH
may be prepared by reacting a compound of formula (13)

in which Pg1 represents an amino protecting group, such as t-
butoxycarbonyl, with a compound of formula R2-COOH, under
conditions known for the formation of an amide bond, for
example as described hereinabove for forming a compound of
formula (I) , followed by deprotection.
The compounds of formula (13) may be prepared by reacting
an appropriate N-protected glycine of formula (14)

in which Pg2 represents an amino protecting group that can be
selectively removed in the presence of Pg1 (for example, when
Pg1 is t-butoxycarbonyl, Pg2 may be benzyloxycarbonyl) , with a
compound of formula (15)
under amide bond forming conditions, followed by selectively-
removing the protecting group Pg2.
Compounds of the formula (10) in which X is CONH may be
5 prepared by deprotecting a compound of the formula (16);

in which Pg3 represents an amino protecting group', such as t-
butoxycarbonyl.
The intermediates of formula (16) and the corresponding
amines without Pg3 are believed to be novel, and are provided
as a further aspect of the invention.
Compounds of formula (16) may be prepared by reacting a
compound of formula (14) with a compound of formula (17)

under amide bond forming conditions. The reaction is
conveniently performed in the presence of diethylcyano-
phosphate. Convenient solvents include amides, such as
dimethylformamide. The temperature is conveniently in the
range of from 0 to 100 °c.
Compounds of formula (17) in which Rr is -(CH2)C-Rc may
be prepared by reacting a compound of formula (18)

in which Pg4 represents an amino protecting group, such as t-
butoxycarbonyl, with a compound of formula (19)
followed by removing the protecting group, Pg4. The reaction
is conveniently performed in the presence of an acid, such as
acetic acid. Convenient solvents include alcohols, such as
ethanol.
Compounds of formula (17) in which Rr is -(CH2)C-RC may
also be prepared by reacting a compound of formula (18) with a
compound of formula (19a)
Z-(CH2)C-RC
in which Z represents a leaving atom or group, such as
methanesulfonyloxy or benzenesulfonyloxy, followed by removing
the protecting group, Pg4.
Compounds of formula (17) in which Rr is -(CH2)C-RC may
also be prepared by reducing compounds of formula (20) or
formula (20A)

in which Pg5 and Pg6 each represent an amino protecting group,
such as t-butoxycarbonyl, followed by removing the protecting
group, Pg5. The reduction is conveniently performed in the
presence of a reducing agent, such as borane, in an ether such
as tetrahydrofuran.
Compounds of formula (20) may be prepared by reacting a
compound of formula (18) with a compound of formula (21)
HOOC-(CH2)C-1-Rc
under amide bond forming conditions.
Alternatively, compounds of formula (20) may be prepared
by reacting a compound of formula (18) with a compound of
formula (21a)
in which X1 is a hydrogen atom, such as bromine, followed by-
reaction with a compound of formula (21b)
HRC
in the presence of a strong base, such as sodium hydride.
Hence the present invention also provides a process for
the preparation of a compound of formula (I) comprising:
a) when -X-X is -CONH-, reacting a compound of formula (10)
with a compound of formula R2-COOH, under amide bond-forming
conditions; or
b) when Rr is - (CH2) C-Rc reacting a compound of formula
(11) with a compound of (12);
wherein R2, X, Y, Cy, c and Rr are as hereinabove defined and
formulae (10) , (11) and (12) are as hereinabove defined,
followed if a salt is required, by forming a physiologically
acceptable salt.
An amino acid of formula (23)

or an N-protected glycine of formula (14) may be prepared (for
example) by one or more of the following methods:
(i) from aryl or heteroaryl aldehydes via the Strecker
synthesis or modifications thereof, via Bucherer-3ergs
hydantoin synthesis, or via the Ugi methodology ("Isonitrile
Chemistry", Ugi I. Ed.; Academic: New York, 1971;145-1999,
"Multicomponent Reactions with Isocyanides", Domling, A.; Ugi,
I. Angew. Chem. Int. Ed. 2000, 39, 3168; "Amino Acid
Derivatives by Multicomponent Reactions", Dyker, G. Angew,
Chem. Int. Ed. Engl. 1997, 36, 1700; and also see "A new Class
of Convertible Isocyanides in the Ugi Four-Component
Reaction", Lindhorst, T. ; Bock H.; Ugi, I. Tetrahedron, 1999,
55, 7411.) with removal and replacement of protecting groups;
(ii) from styrenes via Sharpless methodology (J. Am. Chem.
Soc. 1998,120, 1207-1217)
(iii) from aryl boronic acids via Petasis methodology
(Tetrahedron, 1997, 53, 16463-16470) with removal and
replacement of protecting groups;
(iv) from aryl and heteroaryl acetic acids - via Evan's
azidation (Synthesis, 1997, 536-540) or by oximation, followed
by reduction and addition of protecting groups; or
(v) from existing aryl glycines by manipulation of functional
groups, for example, alkylation of hydroxy groups, palladium
assisted carbonylation of triflates derived from hydroxy
groups and further manipulation of the carboxylic esters to
give carboxylic acids by hydrolysis, carboxamides by
activation of the carboxylic acid and coupling with amines,
amines via Curtius reaction on the carboxylic acid;
(vi) from aliphatic, carbocylic and non-aromatic heterocyclic
aldehydes and ketones using a Horner-Emmons reaction with N-
benzyloxycarbonyl) -a-phosphonoglycine trimethyl ester
(Synthesis, 1992, 487-490); or
(vii) from oximes of formula

in which Pg is a carboxy protecting group, by reduction.
(Oximes in which Cy is a heteroaryl group may be prepared from
compounds of formula
Alternatively, oximes may be prepared by nitrosation of a
compound of formula Cy-CH2-COOPg, or by reaction of
hydroxylamine with a compound of formula Cy-CO-COOPg).
A starting material for the preparation of a compound of
formula (I), where the alpha atom is nitrogen, may be
produced, for example, by reaction of a beta protected
hydrazine (such protection to be chosen as to be compatible
with the subsequent reagents to be employed) with phosgene,
diphosgene, triphosgene or N,N'carbonyl
diimidazole to give a reactive compound of the type
PGNHN(Cy)COCl or PGNHN(Cy)CO-imidazole (wherein PG is a
protecting group),
This intermediate may be used as has been described above
for the carboxylic starting reagents where the alpha atom is
carbon.
The skilled person will be aware that at certain stages
in the synthesis of a compound of formula (I) it may be
necessary to protect a reactive functional group in the
molecule to prevent unwanted side-reactions.
The protection of amino and carboxylic acid groups is
described in McOmie, Protecting Groups in Organic Chemistry,
Plenum Press, NY, 1973, and Greene and Wuts, Protecting Groups
in Organic Synthesis, 2nd. Ed., John Wiley & Sons, NY, 1991.
Examples of carboxy protecting groups include C1_-C6 alkyl
groups such as methyl, ethyl, t-butyl and t-amyl; ary (C1-
C4)alkyl groups such as benzyl, 4-nitrobenzyl, 4-
methoxybenzyl, 3,4-dimethoxybenzyl, 2,4-dimethoxybenzyl,
2,4,6 -trimethoxybenzyl, 2,4,6-trimethylbenzyl, benzhydryl and
trityl; silyl groups such as trimethylsilyl and t-
butyldimethylsilyl; and allyl groups such as allyl and 1-
(tritnethylsilylmethyl)prop-l-en-3-yl.
Examples of amine protecting groups (PG) include acyl
groups, such as groups of formula RCO in which R represents
C1-6 alkyl, C3-10 cycloalkyl, phenyl C1-6 alkyl, phenyl, C1-6
alkoxy, phenyl C1-6 alkoxy, or a C3-10 cycloalkoxy, wherein a
phenyl group may be optionally substituted, for example by one
or two of halogen, C1-C4 alkyl and C1-C4 alkoxy.
Preferred amino protecting groups include
benzyloxycarbonyl (CBz), t-butoxycarbonyl (Boc) and benzyl.
In another aspect the invention relates to a process for
preparing a compound of formula I comprising deprotecting a
compound of formula (I') :
R2'-X-X-Y(Cy')-L-Lp(D)n' (I) '
Wherein R2' is R2 (as hereinabove defined) or protected R2, Cy'
is Cy (as hereinabove defined) or protected Cy and Lp(D)n' is
Lp(D)n (as hereinabove defined) or protected Lp(D)n; providing
at least one protecting group is present.
If necessary physiologically tolerable salts can be
formed using methods known in the art.
It will be understood that the compounds of formula (I)
may be isolated in the form of salts or solvates (which may or
may not be physiologically tolerable) , and that all such salts
and solvates are therefore included within the scope of the
present invention.
All novel intermediates described herein, for example the
compounds of formula

and salts thereof, are provided as further aspects of the
invention.
The compounds of the invention may be administered by any
convenient route, e.g. into the gastrointestinal tract (e.g.
rectally or orally), the nose, lungs, musculature or
vasculature or transdermally. The compounds may be
administered in any convenient administrative form, e.g.
tablets, powders, capsules, solutions, dispersions,
suspensions, syrups, sprays, suppositories, gels, emulsions,
patches etc. Such compositions may contain components
conventional in pharmaceutical preparations, e.g. diluents,
carriers, pH modifiers, sweeteners, bulking agents, and
further active agents. Preferably the compositions will be
sterile and in a solution or suspension form suitable for
injection or infusion. Such compositions form a further
aspect of the invention.
The following are examples of pharmaceutical compositions
of compounds according to the invention.
The above ingredients are mixed and filled into hard
gelatin capsules in 460 mg quantities.
The active ingredient, starch, and cellulose are passed
through a No. 45 mesh U.S. sieve and mixed thoroughly. The
solution of polyvinylpyrrolidone is mixed with the resultant
powders which are then passed through a No. 14 mesh U.S.
sieve. The granules so produced are dried at 50°C and passed
through a No. 18 mesh U.S. sieve. The sodium carboxymethyl
starch, magnesium stearate, and talc, previously passed
through a No. 60 mesh U.S. sieve, are then added to the
granules which, after mixing, are compressed on a tablet
machine to yield tablets each weighing 15 0 mg.
Viewed from this aspect the invention provides a
pharmaceutical composition comprising a serine protease
inhibitor according to the invention together with at least
one pharmaceutically acceptable carrier or excipient. The
pharmaceutical composition may also optionally comprise at
least one further antithrombotic and/or thrombolytic agent.
Viewed from a further aspect the invention provides the
use of a serine protease inhibitor according to the invention
for the manufacture of a medicament for use in a method of
treatment of the human or non-human animal body (e.g. a
mammalian, avian or reptilian body) to combat (i.e. treat or
prevent) a condition responsive to said inhibitor.
Viewed from a further aspect the invention provides a
method of treatment of the human or non-human animal body
(e.g. a mammalian, avian or reptilian body) to combat a
condition responsive to a serine protease inhibitor (e.g. a
condition such as a thrombotic disorder responsive to a factor
Xa inhibitor), said method comprising administering to said
body an effective amount of a serine protease inhibitor
according to the invention.
The dosage of the inhibitor compound of the invention
will depend upon the nature and severity of the condition
being treated, the administration route and the size and
species of the patient. However in general, quantities of
from 0.01 to 100 µmol/kg bodyweight will be administered.
All publications referred to herein are hereby
incorporated by reference.
The invention will now be described further with
reference to the following non-limiting Examples.
Experimental
Abbreviations used follow IUPAC-IUB nomencalture. The
following abbreviations are used throughout: aq. (aqueous),
equiv, ([molar] equivalent), Boc (tertiary-butyloxycarbonyl) ,
CMA (chloroform: methanol, concentrated ammonium hydroxide
80:18:2), DCC (1,3-dicyclohexylcarbodiimide), DCM
(dichloromethane), DEPC (diethyl cyanophosphonate), DIPEA
(diisopropylethylamine), DMEA (dimethylethylamine), DMF
(dimethylformamide), DMSO (dimethyl sulfoxide, perdeuterated
if for NMR), EDCI (1-(3-dimethylaminopropyl)-3-ethyl-
carbodiimide hydrochloride), EtOAc (ethyl acetate), EtOH
(ethanol), HATU ([0-(7-azabenzotriazol-l-yl)-1,1,3,3-tetra-
methyluronium hexafluorophosphate]), HOAt (l-hydroxy-7-aza-
benzotriazole,), HOBt (1-hydroxy-benzotriazole), HPLC (high-
performance liquid chromatography), IS-MS (ion spray mass
spectrum), RPHPLC (reverse phase high-performance liquid
chromatography), SCX (strong cation exchange resin), TFA
(trifluoroacetic acid), THF (tetrahydrofuran), TLC (thin layer
chromatography with Rf as relative mobility), DSC
(differential scanning calorimetry), TGA (thermal gravimetric
analysis).
All solution concentrations are expressed as %Vol./%Vol.
unless otherwise stated. Reagents were obtained from a variety
of commercial sources.
IR means an infrared spectrum was obtained. ^NMR, NMR,
1H-NMR, or 1H NMR means a proton magnetic resonance spectrum
was obtained.
HPLC Analysis (Methods A to D)
(Method A): Vydac C18 (4.6 x 250 mm), elute with a linear
gradient of 90/10 through 50/50 (0.1% TFA in water / 0.1% TFA
in acetonitrile) over 40 min, 1 mL/min.
(Method B) : Waters Symmetry, C18 (4.6 x 250 mm) column. The
elution system consisted of linear gradient from 95:5 (0.2%
TFA in H2O)/(0.2% TFA in CH3CN) to 5:95 (0.2% TFA in H2O)/
(0.2% TFA in CH3CN) over 20 min, followed by (0.2% TFA in
CH3CN) isocratic over 15 min. The flow rate was 1 ml/min. UV
Detection was performed at 254 nm unless otherwise noted.
(Method C) : Shimadzu LC6 gradient system equipped with an
autosampler, a variable wavelength detector at flow rates of
0.4 ml/ min. Eluant A consisted of aqTFA (0.1%) and eluant B
90% MeCN in aq TFA(0.1%) with gradient elution (0 min. 20%B
then 20% to 100% over 15 min.); Luna C18 (2.1x150 mm, 5µM
particle size) .
(Method D) : Microsorb-MV C18 (4.6 x 250 mm) column. The
elution system consisted of a linear gradient from 90:10 (2.5%
TFA in H2O):(2.5% TFA in acetonitrile) to 10:90 (2.5% TFA in
H2O) : (2.5% TFA in acetonitrile) over 25 min at 30 °C and a
flow rate of 1 mL/min. UV Detection was performed at 254 nm
unless otherwise noted.
API-MS (atmospheric pressure chemical ionization mass spectra)
were obtained on a PESciex API 150EX with a heated nebulizer
and nitrogen as the reagent gas in positive ion mode.
CI-MS (Chemical ionization mass spectra) were obtained on a
Shimadzu 5000 direct insertion mass spectrometer in chemical
ionization mode utilizing methane as the reagent gas.
MALDI-TOF, Matrix assisted laser desorption ionisation - time
of flight mass spectrometry, RT, retention time.
In general in this specification, "D-" or "R-" in the name of
a product indicates the product was made beginning with a
chiral starting material, for example D-phenylglycine.
Preparation of Starting Materials and Intermediates
Intermediate substituted glycine compounds for starting
materials and intermediates, including those in which the
amino group and/or the carboxy group is protected,
conveniently may be prepared using one of the procedures
below, or by a similar procedure. It may be convenient or
preferred to change the order of steps in the preparation of a
compound of the invention and to use a similar procedure with
a different intermediate. In particular, it may be convenient
to use an acyl group R2-CO- initially in a preparation, rather
than an amino protecting group.
Abbreviations, in addition to others listed herein,
include: TEMPO: 2,2,6,6-tetramethyl-l-piperidinyloxy, free
radical; (DHQD)2PHAL: hydroquinidine 1,4-phthalazinediyl
diether; r.b. or rb, round bottomed; PPh3, triphenylphosphine;
Boc2O or Boc anhydride: di-tert-butyl dicarbonate.
Preparation of Intermediates KE-1 - KE-5
The following compounds were prepared according to the
indicated method (Method KE-A) from the indicated starting
materials, unless otherwise described.
Intermediate KE-1
Ethyl oxo-quinolin-8-ylacetate.
Method KE-A
To a stirring solution of 8-bromoquinoline (10.1 g, 48.5
mmol) in THF (500 mL) at -78 °C was added dropwise a 1.3 M
solution of sec-butyl lithium (37.3 mL, 48.5 mmol) in
cyclohexane. After 5 min, diethyl oxalate (8 mL, 58.3 mmol)
was added; and the solution was allowed to slowly warm to room
temperature overnight. The next morning, the reaction was
quenched with the addition of saturated aqueous NH4C1; and the
solvent was removed in vacuo. The residue was partitioned
between ethyl acetate and satd aq. NaHCO3; the layers were
separated; and then the aqueous phase was washed with brine,
dried with MgSO4, filtered and concentrated in vacuo. The
residue was chromatographed over silica gel, eluting with 20%
ethyl acetate/hexanes through 25% ethyl acetate/hexanes. The
product containing fractions were combined and concentrated in
vacuo to give 5.88 g (53%) of the title compound.
1H-NMR
IS-MS, m/e 230.1 (M+l)
Intermediate KE-2
Ethyl oxo-quinolin-5-ylacetate.
Prepared from 5-bromoquinoline and diethyl oxalate using
Method KE-A.
1H-NMR
IS-MS, m/e 230.0 (M+l)
Intermediate KE-3
Ethyl oxo-thiazol-5-ylacetate.
To a r.b. flask (500 cm3) under argon, fitted with
ethanol thermometer, septum cap, and dropping funnel, was
added anhydrous ether (100 cm3) with stirring. This was cooled
to -78 °C and 2 M n-butyllithium (60 cm3, 12 0 mmol) was added.
A solution of silyl thiazole (16 g, 16 cm3, 100 mmol) in
anhydrous ether (100 cm3) was then added by dropping funnel
over 3 0 minutes. This was allowed to stir for 1 hour to give
a peach suspension. To this was added diethyl oxalate (16.3
cm3, 17.5 g, 120 mmol) rapidly to give a brown solution,
resulting in a temperature increase to -30 °C. This was
allowed to cool back to -78 °C and stirred for 3 0 minutes.
Reaction monitored by 1H NMR (CDCl3).
The brown solution was poured onto 5% hydrochloric acid
solution (300 cm3) with vigorous stirring for 30 minutes.
Ether layer was separated and washed with saturated
bicarbonate (ca. 80 cm3), dried over magnesium sulphate, and
concentrated in vacuo to give an orange oil. This was
purified by flash chromatography (10% ethyl acetate/hexane) to
give a yellow oil (7.31 g, 39.47 mmol) [40% Yield].
1h NMR (CDCI3); 1.42 (3H, t), 4.45 (2H, q), 8.89 (1H, s), 9.10
(1H, s) .
Intermediate KE-4
Ethyl oxo-thiazol-2-ylacetate.
Prepared from thiazole and diethyl oxalate using Method
KE-A. In this case the temperature was held at -35 °C and n-
butyllithium in hexane was used in place of sec-butyllithium
in cyclohexane.
1NMR
IS-MS, m/e 165.0 (M+l)
Intermediate KE-5
Ethyl oxo-isoquinolin-8-ylacetate.
Prepared from 8-bromoisoquinoline and diethyl oxalate
using Method KE-A, substituting n-butyl lithium in hexanes for
sec-butyl lithium in cyclohexane.
1NMR
IS-MS, m/e 230.0 (M+l)
Analysis for C13H11NO3:
Calcd: C, 68.11; H, 4.84; N, 6.11;
Found: C, 68.11; H, 5.00; N, 6.14.
Preparation of Intermediates OX-1 - OX-9
The following compounds were prepared according to the
indicated method (Method OX-A or Method OX-B) from the
indicated starting materials unless otherwise described.
Intermediate OX-1
Ethyl Hydroxyimino-pyridin-2-ylacetate.
Method OX-A
To a stirring solution of ethyl 2-pyridylacetate (12.6 g,
76.3 mmol) in acetic acid (19 mL) at 5 °C was added a solution
of sodium nitrite (6.05 g, 87.7 mmol) in water (12 mL) at a
rate sufficient to maintain the internal temperature below
15 °C. After complete addition and an additional 30 min, an
additional 30 mL of water were added. The resulting white
precipitate was filtered, washed with water, satd ag. NaHCO3,
and again with water. The solid was then dried under vacuum
to give 14.1 g (95%) of the title compound.
1H-NMR
IS-MS, m/e 194.3 (M+l)
Analysis for C9H10N2O3:
Calcd: C, 55.67; H, 5.19; N, 14.43;
Found: C, 55.79; H, 5.14; N, 14.13.
Intermediate OX-2
Ethyl Hydroxyimino-pyridin-3-ylacetate.
Using the procedure of Tikk et al [Acta. Chimica,
Hungarica, 114(3-4), 355], a mixture of ethyl hydroxyimino-
pyridin-3-yl-acetate and n-butyl hydroxyimino-pyridin-3-yl-
acetate was prepared from ethyl 3-pyridinylacetate and n-butyl
nitrite.
1H-NMR
IS-MS, m/e 195 (M+l), 223.1 (M+l)
Intermediate OX-3
Ethyl Hydroxyimino-quinolin-8-ylacetate.
Method OX-B
To a stirring solution of ethyl oxo-quinolin-8-yl-acetate
(5.5 g, 24 mmol) in ethanol (140 mL) was added sodium acetate
(2.16 g, 26.4 mmol) followed by hydroxylamine hydrochloride
(2.67 g, 38.4 mmol). The mixture was heated to reflux; and,
after 7 h, the heating mantle was removed and the solution was
allowed to stir overnight at room temperature. The next
morning, the solvent was removed in vacuo and the residue was
partitioned between ethyl acetate and satd aq. NaHCC>3 . The
layers were separated and the organic phase was washed with
brine, dried with Na2SO4, filtered and concentrated in vacuo.
The resulting foam was recrystalized from
dichloromethane/hexanes to give an initial crop of 2.5 g of
the title compound as an off-white solid, followed by 0.31 g
of a second crop. The mother liquor was then concentrated in
vacuo, the residue was dissolved in a minimal amount of
dichloromethane. The solution was then chromatographed over
silica gel, eluting with 30% ethyl acetate/hexanes, then 40%
ethyl acetate/hexanes, and finally with ethyl acetate. The
product containing fractions were combined and concentrated in
vacuo to give 1.94 g of the title compound for a combined
yield of 4.75 g (81%).
1H-NMR
IS-MS, m/e 245.0 (M+l)
Intermediate OX-4
Ethyl Hydroxyimino-quinolin-5-ylacetate.
Prepared from ethyl oxo-quinolin-5-yl-acetate using
Method OX-B.
1H-NMR
IS-MS, m/e 245.0 (M+l)
Intermediate OX-5
Ethyl Hydroxyimino-thiazol-5-ylacetate.
To a r.b. flask (500 cm3) was added the ethyl oxo-
thiazol-5-ylacetate (6.30g, 34.02 mmol) to ethanol (ca. 180
cm3) with stirring. Sodium acetate (3.06g, 37.30 mmol) and
hydroxylamine hydrochloride (3.78g, 54.43 mmol) were then
added to give an off-white suspension. This was brought to
reflux at 85 °C for 1 hour. Reaction monitored by TLC (60%
hexane/ethyl acetate; s.m. r.f 0.5, prod. r.f. 0.3.) .
Reaction cooled and concentrated in vacuo. Product taken up
in ethyl acetate (c.a. 200 cm3) and washed with 5%
hydrochloric acid solution. Ethyl acetate layer was dried
over magnesium sulphate and evaporated to dryness to give a
cream solid (6.372g, 31.825 mmol) [94% Yield].
1h NMR (CDC13); 1.40 (3H, m) , 4.40 (2H, m) , 8.06 (V3H, s),
8.78 (1/3H, s), 8.95 (2/3H, s), 8.98 (2/3H,s).
Intermediate OX-6
Ethyl a-0ximino-thiazole-4-acetate.
To a 2 necked r.b. flask (100 cm3) with ethanol
thermometer, concentrated sulphuric acid (25 cm3) was added
and cooled to 0 °C with stirring. To this solution was added
the ethyl a-oximino-2-aminothiazole-4-acetate (5.00 g, 23.231
mmol) . Water- (10 cm3) was then added and cooled to -10 °C. A
solution of sodium nitrite (1.683 g, 24.393 mmol) in water (5
cm3) was then added slowly over an hour keeping the
temperature below -5 °C.
To a separate r.b. flask (500 cm3), water (130 cm3) was
added and cooled to 3 °C. The reaction solution was poured in
to the cold water with stirring and then cooled to -5 °C. To
this solution, 50% hypophosphoric acid (90 cm3) was added
dropwise over 10 minutes keeping the temperature at -5 °C. The
solution was allowed to warm to room temperature and stirred
overnight. The product was extracted with diethyl ether (ca.
3x150 cm3) and washed with water. The ether layer was
concentrated in vacuo and treated to flash chromatography (50%
ethyl acetate/n-hexane) to yield a orange oil upon
concentration in vacuo (0.60 g, 3.00 mmol) [13% yield] .
1H NMR (CDC13) 1.35 (3H, m) , 4.35 (2H, m) , 8.4 (1H, s) , 8.9
(1H, S), 14.4 (1H, s).
Intermediate OX-7
Ethyl a-0ximino-2-methylthiazole-4-acetate.
This was prepared from ethyl-?-chloro-a-oximino-
acetoacetate (1.44g) using the method of Hatanaka et al.
{Journal of Medicinal Chemistry, 1973, 16(9), 978-984) to
yield the titled compound (0.64 g) .
1H NMR (CDCl3) 1.35 (3H, t), 2.7 (3H, s), 4.35 (2H, q), 8.2
(IK, s).
Ethyl ?-Chloro-a-oximinoacetoacetate.
This was prepared from ethyl oximinoacetoacetate (1.73 g)
using the method of Hatanaka et al. (Journal of Medicinal
Chemistry, 1973, 16(9), 978-984) to yield the titled compound
(1.44g).
1H NMR (CDCl3) 1.25 (3H, t) , 4.3 (2H, q) , 4.55 (2H, s) , 9.45
(1H, s), contains 20% starting material by NMR.
Ethyl Oximinoacetoacetate
This was prepared from ethyl acetoacetate (lO.OOg) using
the method of Fischer (Organic Synthesis Coll. Vol. 3, 513-
516) to yield the titled compound (12.45 g).
1H NMR (CDC13) 1.25 (3H, t), 2.35 (3H, s), 4.3 (2H, q) , 8.8
(1H, br.).
Intermediate OX-8
Ethyl hydroxyimino-thiazol-2-ylacetate.
Prepared from ethyl oxo-thiazol-2-ylacetate using Method
OX-B.
1NMR
IS-MS, m/e 198.9(M-l)
Intermediate OX-9
Ethyl,hydroxyimino-isoquinolin-8-ylacetate.
Prepared from ethyl oxo-isoquinolin-8-ylacetate using
Method OX-B.
1NMR
IS-MS, m/e 245.0(M+i)
Analysis for C13H12N2O3:
Calcd: C, 63.93; H, 4.95; N, 11.47;
Found: C, 63.68; H, 4.60; N, 11.34.
Preparation of Intermediates AL-1 - AL-3
The following compounds were prepared according to the
indicated method (Method AL-A or Method AL-B) from the
indicated starting materials, unless otherwise described.
Intermediate AL-1
R-3 -Bromo- (1-1-butoxycarbonylamino-2-hydroxyethyl)benzene.
Method AL-A
Sodium hydroxide (3.33 g, 83.25 mtnol) was dissolved in
water (22 0 mL), and 2 0 mL of the resulting solution was
removed and added to potassium osmate (410 mg, 1.11 mmol).
The remaining sodium hydroxide solution (2 00 mL) was added to
a stirred solution of t-butyl carbamate (9.9 g, 84.5 mmol) in
n-propanol (110 mL) followed by freshly prepared t-butyl
hypochlorite (9.65 mL; 83.5 mmol). After stirring for 5 min,
the solution was cooled to 0 °C. A solution of (DHQD)2PHAL
(1.30 g, 1.67 mmol) in n-propanol (110 mL) was added, followed
by a solution of 3-bromostyrene (5 g, 27.31 mmol) in n-
propanol (22 0 mL), followed by dropwise addition of the
potassium osmate/sodium hydroxide solution. The reaction was
stirred overnight. Saturated aqueous sodium sulfite (150 mL)
was added, and the reaction was stirred for 15 min. The
aqueous layer was separated and extracted with ethyl acetate
(3x 200 mL). The combined organic layers were washed with
brine and dried over MgSO4. Removal of solvent under vacuum
gave the crude product which was purified by chromatography
(silica, 3:2 hexane:ethyl acetate then rechromatographed
loading with toluene, gradient elution with hexane - 4:1
hexane:ethyl acetate) to give the title product (4.18 g, 49%).
Melting Point = 90-91 °C
1H NMR (CDCI3).
Intermediate AL-2
R-3-Methoxycarbonyl-(1- t-butoxycarbonylamino-2-hydroxy-
ethyl) benzene.
Method AL-B
In a glass liner containing a stirrer bar was placed
Pd(OAc)2 (871 mg, 3.88 mmol), PPh3 (1.96 g, 7.47 mmol, NaOAc
(1.48 g, 18.04 mmol) and DMF (82 mL). To this stirred
solution was added a solution of R-3-bromo-(1-t-butoxy-
carbonylamino-2-hydroxyethyl)benzene (4.27 g, 13.5 mmol) in
MeOH (82 mL). The resulting solution was purged with nitrogen
and placed in a stirred pressure vessel. The system was
charged to 4.1 bar (60 psig) of CO and heated at 95 °C for 36
h. The mixture was cooled to room temperature, filtered
through diatomaceous earth, and partitioned between ethyl
acetate and water. The organic layer was washed with water
(3x) and brine (1x) and dried over MgSO4. Removal of solvent
under vacuum gave the crude product which was purified by
chromatography (silica gel, gradient elution with 3 0-35% ethyl
acetate/hexane) to provide the title product (3.53 g, 89%).
Melting Point = 73-75 °C with decomposition
1H NMR (CDCI3).
API-MS, m/e = 240 (M-C4H9+I).
Intermediate AL-3
R-3 -Cyano- (1-t-butoxycarbonylamino-2-hydroxyethyl) benzene.
Prepared from 3-cyanostyrene using Method AL-A.
3-Cyanostyrene was prepared using the method described below.
Melzing Point = 7 6 °C.
1H NMR (CDCI3).
Preparation of 3-Cyanostyrene.
To a stirred suspension cf methyltnphenylphosphonium
bromide (75 g, 209.71 mmol) in dry THF (75 0 mL) at 0 °C under
nitrogen was added dropwise n-BuLi (83 mL, 2.5 M in hexanes,
20 7.50 mmol). The mixture was warmed to room temperature. 3-
Cyanobenzaldehyde (25 g, 190.65 mmol) was added as a solid in
5 g batches, and the mixture was stirred at room temperature
overnight. The reaction was quenched in water, and the
solvent was removed under vacuum. The residue was dissolved
in the minimal amount of THF, and triphenylphosphine oxide was
precipitated using ether. The solid was filtered through
diatomaceous earth, and the filtrate was concentrated.
Distillation by Kugelrhor at 90 °C/33 Pa (0.25 mm Hg) gave the
product as a colorless oil (15.5 g, 62%).
Boiling Point = 90 °C at 0.25 mmHg.
lH NMR (CDC13).
Preparation of Intermediates PAE-1 - PAE-18
The following compounds were prepared according to the
indicated method (Method PAE-A, Method PAE-B, Method PAE-C,
Method PAE-D or PAE-E) from the indicated starting materials,
unless otherwise described.
Intermediate PAE-1
Boc-D,L-(2-pyridinyl)glycine Ethyl Ester.
Method PAE-A
To a solution of ethyl hydroxyimino-pyridin-2-yl-acetate
(7.8 g, 40.15 g) in ethanol (175 mL) and glacial acetic acid
(20 mL) was added 5% Pd/C, and the mixture was shaken in a
hydrogenation apparatus under an atmosphere of hydrogen at 4.1
bar (45 psig) for 4 h. The mixture was filtered through
diatomaceous earth and concentrated in vacuo. The residue was
dissolved in THF/H2O (l/l, 240 mL) and treated with di-tert-
butyl dicarbonate (14.23 g, 65.2 mmol) and sodium bicarbonate
(27.4 g, 326 mmol). After stirring at room temperature for
2 h, the solution was concentrated in vacuo and the residue
was partitioned between EtOAc and water. The organic phase
was washed with brine, dried over magnesium sulfate, filtered
and concentrated in vacuo. The crude material was purified
via chromatography over silica gel, eluting with a stepwise
gradient of 10-20% ethyl acetate in dichloromethane to give
8.11 g (72%) of the title compound as a yellow oil.
1H-NMR
IS-MS, m/e 281.1 (M+l)
Intermediate PAE-2
Boc-D,L-(3-pyridinyl)glycine Ethyl Ester.
Prepared from ethyl hydroxyimino-pyridin-3-ylacetate
using Method PAE-A.
1H-NMR
IS-MS, m/e 281.1 (M+l)
Intermediate PAE-3
Boc-D,L-(8-quinolinyl)glycine Ethyl Ester.
Method PAE-B
To a stirring solution of ethyl hydroxyimino-quinolin-8-
ylacetate (2.4 g, 9.8 mmol) in 50% aq. formic acid (50 mL) at
0 °C was added zinc dust (2 g, 31 mmol). After 1 min, the
mixture was filtered through diatomaceous earth and the
filtrate was loaded onto an SCX column. After washing the
column with methanol, the product was eluted with a 3 to 1
mixture of dichloromethane and (2 N NH3 in methanol). The
product containing fractions were combined and concentrated in
vacuo to give 2.24 g of light orange oil (IS-MS, m/e 231.0
(M+l)).
The oil (2.14 g, 9.3 mmol) was dissolved in THF (40 mL)
and to this stirring solution was added triethylamine (1.4 mL,
10.2 mmol), followed by di-tert-butyl dicarbonate (2.1 g, 9.8
mmol). After 45 min, the solvent was removed in vacuo and the
residue was partitioned between ethyl acetate and water. The
organic phase was then washed with satd aq. NaHCO3, dried with
Na2SO4, filtered and concentrated in vacuo. The residue was
dissolved in a minimum volume of dichloromethane and
chromatographed over silica gel, eluting with 5% ethyl acetate
in hexanes. The product containing fractions were combined
and concentrated to give 2.5 g (81%) of the title compound.
1H-NMR
IS-MS, m/e 331.0 (M+l)
Intermediate PAE-4
Boc-D,L-(5-quinolinyl)glycine Ethyl Ester
Prepared from ethyl hydroxyimino-quinolin-5-ylacetate
using Method PAE-B.
1H-NMR
IS-MS, m/e 331.0 (M+l)
Intermediate PAE-5
N-4-Methoxybenzoyl-N-2,4-dimethoxybenzyl-D/L-(2-trifluoro-
methylphenyl)glycine Methyl Ester.
Method PAE-C
To 2-trifluoromethylbenzaldehyde (1 g, 5.7 mmol) with
stirring was added 2,4-dimethoxybenzylamine (0.86 mL, 5.7
mmol) and methanol (2 mL). After 5 min, the solution was
diluted with toluene 100 mL and concentrated in vacuo (twice).
The residue was then dissolved in anhydrous methanol (12 mL)
and 1,l-dimethyl-2-(methoxycarbonyloxy)ethyl isonitrile
[Tetrahedron, 55 (1999) 7411-7420] (0.9 g, 5.7 mmol) was
added, followed by 4-methoxybenzoic acid (0.87 g,, 5.7 mmol).
After stirring for 72 h, the solvent was removed in vacuo and
the residue was chromatographed over silica gel, eluting with
a step gradient of 30% ethyl acetate in hexanes through 50%
ethyl acetate in hexanes. The product containing fractions
were combined and concentrated in vacuo; and then the residue
was dissolved in ethyl acetate, washed with satd aq. NaHCO3,
dried with Na2SO4, filtered and concentrated to give 1.76 g
(48%) of thick oil (NMR, IS-MS, m/e 633.0 (M+l) ). The oil
(0.5 g, 0.79 mtnol) was then dissolved in toluene (5 mL) and
concentrated in vacuo (twice) to give a white foam. The
residue was then dissolved in THF (3 mL) and potassium tert-
butoxide (0.11 g, 0.95 mmol) was added. After 15 min, 12 N
HC1 (0.079 mL, 0.95 mmol) was added and the solution was
allowed to stand overnight in the refrigerator. The next
morning, the solvent was removed and the residue was
chromatographed over silica gel, eluting with 30% ethyl
acetate in hexanes. The product containing fractions were
combined and concentrated to give 0.32 g (79%) of the title
compound.
1H-NMR
IS-MS, m/e 518.0 (M+l)
Intermediate PAE-6
BOC-D,L-(5-thiazolyl)glycine ethyl ester.
To a r.b. flask (250 cm3),, D,L-(5-thiazolyl)glycine ethyl
ester (4.60 g, 24.7 mmol) was added to tetrahydrofuran
(c.a. 100 cm3) with stirring to give a yellow solution. BOC
anhydride (5.439g, 24.948 mmol) and triethyl amine (3.79 cm3,
2.75g, 27.17 mmol) were then added with stirring for 1 hour.
Reaction monitored by TLC (60% hexane/ethyl acetate; s.m. r.f
0.05, prod. r.f. 0.5.) . The reaction concentrated in vacuo
and product taken up in ethyl acetate {c.a. 150 cm3), washed
with 5% hydrochloric acid solution {c.a. 3 0 cm3), and
saturated bicarbonate {ca. 3 0 cm3). Ethyl acetate layer was
dried over magnesium sulphate and evaporated to dryness to
give an orange oil (7.42 g, -24.70 mmol) [-100% Yield].
1H NMR (CDC13); 1.30 (3H, t), 1.48 (9H, s), 4.28 (2H, q), 5.68
(1H, br.), 7.88 (1H, s) , 8.78 (1H, s).
D,L-(5-Thiazolyl)glycine Ethyl Ester.
To a r.b. flask (250 cm3), was added 5-thiazolyl-
oximinoacetic acid ethyl ester (6.37 g, 31.825 mmol) to
ethanol (c.a. 80 cm3) with stirring. 50% Formic acid solution
(50 cm3) was added with zinc dust (5.10 g, 81.83 mmol) and
allowed to stir overnight. Reaction monitored by TLC
(60% hexane/ethyl acetate; s.m. r.f 0.3, prod. r.f. 0.05.).
Reaction solution filtered over diatomaceous earth and
filtrate concentrated in vacuo. This was basified to pH 9
with anhydrous potassium carbonate and product taken up in 3:1
chloroform/isopropanol solution (c.a. 200 cm3). This was
washed with saturated bicarbonate (c.a. 50 cm3), dried over
magnesium sulphate and concentrated in vacuo to give a brown
oil (4.60 g, 24.70 mmol) [78% Yield] .
1H NMR (CDC13); 1.25 (3H, t), 1.95 (2H, br.), 4.22 (2H, q),
4.85 (1H, S), 7.80 (1H, s), 8.70 (1H, s).
Intermediate PAE-7
N-Boc-D,L-(4-thiazolyl)glycine ethyl ester
To a solution of D,L-(4-thiazolyl)glycine ethyl ester
(0.460 g, 2.470 mmol) in tetrahydrofuran (20 cm3), was added
di-tert-butyl dicarbonate (0.53 0 g, 2.470 mmol) and
triethylamine (0.344 cm3, 2.470 mmol). This was allowed to
stir for 1 hour and the solution concentrated in vacuo. The
oil was taken up in ethyl acetate {c.a. 50 cm3) washed with
0.5% hydrochloric acid solution {c.a. 20 cm3), and saturated
sodium bicarbonate solution {c.a. 2 0 cm3) . This was then dried
over magnesium sulphate and concentrated in vacuo to yield an
orange oil (0.709 g, 2.477 mmol) [-100% yield].
1H NMR (CDCI3) 1.15 (3H, t) , 1-35 (9H, s), 4.1 (2H, m) , 5.45
(1H, d) , 5.75 (1H, d) , 7.3 (1H, d) , 8.7 (1H, d).
D,L-(4-Thiazolyl)glycine Ethyl Ester.
This was prepared from ethyl-a-oximino-thiazole-4-acetate
(0.60 g) using the method of Hatanaka et al. (Journal of
Medicinal Chemistry, 1973, 16(9), 978-984) to yield the titled
compound (0.46 g).
lH NMR (CDC13) 1.25 (3H, t), 1.8-2.3 (2H, br.), 4.1 (2H, m),
4.75 (1H, s), 7.25 (1H, d), 8.7 (1H, d).
Intermediate PAE-8
N-Boc-D,L-(2-methylthiazol-4-yl)glycine Ethyl Ester
To a solution of D,L-(2-methylthiazol-4-yl)glycine ethyl
ester (0.397 g, 1.982 tnmol) in tetrahydrofuran (20 cm3), was
added di-tert-butyl dicarbonate (0.475 g, 2.180 mmol) and
triethylamine (0.304 cm3, 2.180 mmol). This was allowed to
stir for 1 hour and the solution concentrated in vacuo. The
oil was taken up in ethyl acetate (c.a. 5 0 cm3) washed with
0.5% hydrochloric acid solution {c.a. 20 cm3), and saturated
sodium bicarbonate solution (c.a. 2 0 cm3). This was then
dried over magnesium sulphate and concentrated in vacuo to
yield a yellow oil (0.654 g, 2.177 mmol) [~100% yield].
1H NMR (CDCl3) 1.1 (3H, s), 1.35 (9H, s), 2.6 (3H, s), 4.15
(3H, m), 5.3 (1H, d) , 5.7 (1H, s), 7.0 (1H, s).
D,L-(2-Methylthiazol-4-yl)glycine Ethyl Ester.
This was prepared from ethyl-a-oximino-2-methylthiazole-
4-acetate (0.62 g) using the method of Hatanaka et al.
{Journal of Medicinal Chemistry, 1973, 16(9), 978-984) to
yield the titled compound (0.40 g).
1H NMR (CDCI3) 1.15 (3H, t), 1.95 (2H, br.), 2.6 (3H, s), 4.15
(2H, m), 4.65 (1H, s) , 6.95 (1H, s) .
Intermediate PAE-9
Boc-R-(4-Hydroxyphenyl)glycine Methyl Ester
To a stirred mixture of R-(4-hydroxyphenyl)glycine methyl
ester hydrochloride (14g) and sodium bicarbonate (11.7 g) in
THF (150 mL) and water (50 mL), was added in one portion, di-
t-butyl dicarbonate (15.9 g). The mixture was stirred rapidly
to allow thorough mixing for 4 h. Hexane (75 mL) was added
and the organic layer separated and washed with satd sodium
bicarbonate solution, then brine and then dried with magnesium
sulphate. The drying agents was filtered off and washed with
a little THF and evaporated to dryness, finishing with a high
vacuum pump to remove the last traces of di-t-butyl
dicarbonate. Yield 19.7 g, 96%.
1H NMR
R-(4-Hydroxyphenyl)glycine Methyl Ester Hydrochloride.
To a dry 250 mL three necked round bottom flask, equipped
with a low temperature thermometer, a septum for nitrogen
coverage and another for introduction of thionyl chloride by
syringe, was added R-4-hydroxyphenylglycine (12.5 g) and dry
methanol (24 mL). The mixture was stirred (magnetic stirrer)
and cooled to an internal temperature of -20 °C using
cardice/acetone. Using a syringe, thionyl chloride was added
dropwise to the cooled mixture over a period of 10 min.
(Care: the reaction of thionyl chloride with methanol is very
exothermic and rate of addition should be such that the
thionyl chloride is efficiently stirred into the mixture and
that the temperature does not rise above -2 0 °C. Once the
addition was complete the mixture was allowed to warm to room
temperature overnight (16-18 h). Dry ether (150 mL) was added
and the white ppt. that formed was filtered off, washed with a
little more ether and dried. Yield 15.5 g, 95%.
lH NMR
Intermediate PAE 10
Boc-R-(4-Trifluc omethanesulphonyloxyphenyl)glycine Methyl
Ester Hydrochlor.de.
To a stirrel solution of Boc-R-(4-hydroxyphenyl)glycine
methyl ester (19 g) in dichloromethane (400 mL) was added 2,6-
lutidine (9.44 mL) and 4-dimethylaminopyridine (1.65 g) and
the mixture cooled in an ice bath. Trifluoromethanane-
sulphonic anhydride (13.74 mL) was added over a period of 5
min, and then the reaction left to warm to room temperature
over 4 h. The organic solution was washed with water (2 x 150
mL), 1 N HC1 (2 x 150 mL), and then saturated sodium
bicarbonate (15 0 mL). The organics were dried with magnesium
sulphate and then evaporated to an oil. The mixture was
purified using flash chromatography (Si02 250 g, eluting with
1:1 hexane/dichloromethane and then neat dichloromethane).
Pure product fractions were combined and evaporated, finishing
with a high vacuvm pump to remove all traces of solvent, to
give a white solid, 19 g, 77%.
1H NMR
Intermediate PAE 11
Boc-R- (4-Methoxyoirbonylphenyl)glycine Methyl Ester.
Method PAE-D
Boc-R-4-tert fluoromethanesulphonyloxyphenylglycine methyl
ester (15 g), n thanol (32.6 mL), bis-1,3-diphenyl-
phosphinylpropc- 5 (448 mg), palladium (II) acetate (255 mg),
triethylamine 2 mL) and dimethylformamide (72 mL) were
placed in the gas liner of pressure (Parr) reactor and the
reactor assembl The vessel was pressurised to -0.68 bar
(10 psig) with nitrogen and the gas released (repeated five
times to remove all oxygen from the system) . Carbon monoxide
gas was then carefully introduced (use extreme care -the gas
cylinder is pressurised to far beyond the bursting disc
pressure of the Parr, ideally use a pressure regulator to
reduce the pressure to - 6.8 bar, 100 psig) to ~1.4 bar (20
psig) and released three times (into the back of a fume hood) .
Carbon monoxide was then added to ~6.8 bar (100 psig) and the
stirrer started. The vessel was slowly heated to 65 °C
internal temperature and then stirred at 65 °C overnight. (At
the early stages more carbon monoxide was added to maintain
-6.8 bar, 100 psig.) A sample was removed after 18 h and
examined by tlc. When complete, the reaction was cooled to
-30 °C, the gas released and the vessel flushed five times
with nitrogen as before. The reaction mixture was partitioned
between ethyl acetate and water, and the organic layer washed
with 1 M hydrochloric acid and then saturated sodium
bicarbonate. The solution was dried with MgSO4 and
evaporated. Flash chromatography of the resulting oil gave
the product, pure by tlc, 10.6 g, 90%.
1H NMR
Intermediate PAE-12
Boc-R-(4-Benzyloxycarbonylphenyl)glycine Methyl Ester
Prepared from Boc-R-4-trifluoromethanesulphonyloxy
phenylglycine methyl ester and benzyl alcohol using Method
PAE-D.
1H NMR
Intermediate PAE-13
Boc-R-(4-Carboxyphenyl)glycine Methyl Ester.
Boc-R-(4-benzyloxycarbonylphenyl)glycine methyl ester
(500 mg) was dissolved in THF containing Pd/C 10% (100 mg) and
hydrogenated at l atm for 2 h. Removal of the catalyst by
filtration and evaporation of solvent gave Boc-R-(4-carboxy-
phenyUglycine methyl ester (330 mg, 87%) .
1H NMR
Intermediate PAE-14
Boc-R-(4-carboxamidophenyl)glycine Methyl Ester.
Method PAE-E
To a solution of Boc-R-(4-carboxyphenyl)glycine methyl
ester (3.5 g) in DMF (30 mL) was added EDCI (2.60 g, 1.36
mmol) and HOBt (1.4 g, 10.4 mmol), and the mixture stirred for
10 min before cooling in a ice bath and bubbling in ammonia
gas for 5 min. The mixture was stirred for 2 h at room
temperature and then diluted with ethyl acetate and washed
with water. The aqueous solution was extracted with a little
ethyl acetate and the combined organics washed with brine.
The organic solution was evaporated to an oil which was
purified by flash chromatography (SiO2 - dichlorornethane/
ethyl acetate 0 - 25%) to give Boc-R-(4-carbox-
amidophenyl)glycine methyl ester (1.7 g, 48%).
1H NMR
Intermediate PAE-15
Boc-R-(4-methylcarboxamidophenyl)glycine Methyl Ester.
Prepared from Boc-R-(4-carboxyphenyl)glycine methyl ester
and methylamine using Method PAE-E.
1H NMR
Intermediate PAE-16
N-4-Methoxybenzoyl-N-2,4-dimethoxybenzyl-D,L- (quinolin-4-
yl)glycine Methyl Ester.
Prepared from quinoline-4-carboxaldehyde using Method
PAE-C.
1H NMR
Intermediate PAE-17
Ethyl Boc-D,L-thiazol-2-ylglycine.
Prepared from ethyl hydroxyimino-thiazol-2-ylacetate
using Method PAE-B. In this case, reaction with Zn/formic
acid was conducted over 15 min.
1NMR
IS-MS, m/e 287.0 (M+l)
Intermediate PAE-18
Ethyl Boc-D,L-isoquinolin-8-ylglycine.
Prepared from ethyl hydroxyimino-isoquinolin-8-ylacetate
using Method PAE-B. In this case, reaction with Zn/formic
acid was conducted over 30 min, followed by concentration and
partitioning of the residue between 3/1 chloroform/isopropanol
and satd aq. NaHCO3. The Boc protection was carried out as
previously described. Purification was performed using silica
gel chromatography (Biotage Quad System) eluting with 10%
ethyl acetate in methylene chloride.
1NMR
IS-MS, m/e 331.0 (M+l)
Analysis for C18H22N2O4:
Calcd: C, 65.44; H, 6.71; N, 8.48;
Found: C, 65.05; H, 6.67; N, 8.49.
Preparation of Intermediates PAA-1 - PAA-28
The following compounds were prepared according to the
indicated method (Method PAA-A, Method PAA-B, Method PAA-C,
Method PAA-D, Method PAA-E or Method PAA-F) from the indicated
starting materials, unless otherwise described.
Intermediate PAA-1
Boc-D,L-(2-chlorophenyl) glycine.
Method PAA-A
2-Chlorobenzaldehyde (20 mmol, 2.252 mL) and 2,4-di-
methoxybenzylamine (20 mmol, 3.004 mL) were added together and
stirred for 2 hours. DCM (5 mL) was added and any water
separated and removed, tert-Butyl isonitrile (2 0 mmol, 2.2 62
mL) was added and stirred for 10 min, followed by acetic acid
(20 mmol, 1.145 mL). Stirring was continued for 3 days. The
reaction mixture was then treated with TFA (30 mL) and
triethylsilane (5 mL). After 3 h the mixture was evaporated
to dryness, 6 M HC1 (100 mL) added, and the whole refluxed
overnight at 13 0 °C, stirring rapidly. The mixture was
allowed to cool and extracted with EtOAc (50 mL x 2); the
aqueous fraction was evaporated to dryness and treated with
2 M NaOH solution. The mixture was extracted with EtOAc (50
mL x 2) ; excess boc anhydride (5.2 g) in dioxane (20 mL) was
added to the aqueous fraction and stirred overnight. The
mixture was extracted with diethyl ether (100 mL x 2),
acidified to pH 1 (cone HCl) and extracted with EtOAc (50 mL x
2). The combined organic fractions were washed with water and
evaporated to dryness under high vacuum. The product Boc -2-
chlorophenylglycine (4.252 g, 74.5%)
1H NMR (CD3CN/D2O) 7.3 (4H, m); 5.5 (1H, s); 1.3 (9H, s). MS
286 (M+l)
Intermediate PAA-11
(R) -Benzyloxycarbonyl- (2-chlorophenyl)glycine.
Prepared from 2-chlorostyrene using the method of
Sharpless et al J.A.C.S. (1998) Voll20 No.6 1207-1217.
Intermediate PAA-1, alternative preparation
Boc-D,L-(2-chlorophenyl)glycine.
Prepared from 2-chlorobenzaldehyde using method PAA-F. In
this case, the reaction temperature was not controlled upon
addition of 2-chlorobenzaldehyde and the reaction was allowed
to stir for 2 h. Extraction of the intermediate aminonitrile
was performed with ethyl ether in place of ethyl acetate and
was further purified by addition of HC1 gas to the ethereal
extracts followed by decantation of the mother liquor to
isolate the semisolid hydrochloride salt. BOC protection of
the amino acid was performed from 0 °C to room temperature
over a period of one hour and the final extraction was
performed with ethyl acetate in place of ethyl ether.
1H-NMR
IS-MS m/e 284 (M-l)
Intermediate PAA-2
Boc-D,L-(3-fluorophenyl)glycine.
Prepared from 3-fluorobenzaldehyde using Method PAA-A.
1H NMR (CD3CN/D2O) 7.3 (1H, m), 7.1(3H, m); 5.2 (1H, s); 1.3
(9H, S). MS 270 (M+l)
Intermediate PAA-3
Boc-D,L-(4-fluorophenyl)glycine.
Prepared from 4-fluorobenzaldehyde using Method PAA-A.
1H NMR (CD3CN/D2O) 7.3 (2H, m); 6.9 (2H, m), 5.0 (1H, s); 1.3
(9H, S). MS 270 (M+l)
Intermediate PAA-4
Boc -D,L-(2-methylphenyl)glycine.
Prepared from 2-methylbenzaldehyde using Method PAA-A.
1H NMR (CD3CN/D2O) 7.3 (4H, m); 5.5 (1H, s); 2.5 (3H, s); 1.3
(9H, s). MS 266 (M+l)
Intermediate PAA-5
Boc-D,L-(3-thienyl)glycine.
Prepared from 3-thiophenecarboxaldehyde using Method PAA-
A.
1h NMR (CD3CN/D2O) 7.5 (2H, m); 7.1 (1H, d); 5.3 (1H, s); 1.3
(9H, S). MS 258 (M+l)
Intermediate PAA-6
Boc-D,L-(2-fluorophenyl)glycine.
Was obtained by treating D,L-2-fluorophenylglycine
(Aldrich) with Boc anhydride (1.1 eq) and 2 M NaOH (1 eq) in
ethanol. Aqueous work up as described above yielded the
protected amino acid.
1H NMR
Intermediate PAA-7
Boc-D,L-(2-methoxyphenyl)glycine.
Prepared from 2-methoxybenzaldehyde using Method PAA-A.
1H NMR
Intermediate PAA-7, alternative preparation
Boc-D,L-(2-methoxyphenyl)glycine.
Prepared from 2-methoxybenzaldehyde using method PAA-F.
In this case, the reaction was cooled to 0 °C before addition
of 2-methoxybenzaldehyde and was then allowed to stir at room
temperature overnight. Extraction of the intermediate
aminonitrile was performed with ethyl ether in place of ethyl
acetate and was further purified by addition of 1 M HC1 in
ethyl ether followed by filtration of the crystalline
hydrochloride salt. BOC protection of the amino acid was
performed from 0 °C to room temperature over a period of three
hours, and the final extraction was performed with
dichloromethane in place of ethyl ether.
1H-NMR
IS-MS m/e 280.1 (M-l)
Analysis for C14H19NO5
Calcd: C, 59.78; H, 6.81; N, 4.98;
Found: C, 59.68; H, 6.78; N, 4.95.
Intermediate PAA-8
Boc-D,L-(2-trifluoromethyl)phenylglycine.
Prepared from 2-trifluoromethylbenzaldehyde using Method
PAA-A.
lH NMR
Intermediate PAA-8, alternative preparation
Boc-D,L-(2-trifluoromethylphenyl)glycine.
Prepared from 2-trifluoromethylbenzaldehyde using method
PAA-F. In this case, the reaction temperature was not
controlled upon addition of 2-trifluoromethylbenzaldehyde and
the reaction was allowed to stir for 2 h. Extraction of the
intermediate aminonitrile was performed with ethyl ether in
place of ethyl acetate and was further purified by addition of
HCl gas to the ethereal extracts followed by decantation of
the mother liquor to isolate the semisolid hydrochloride salt.
BOC protection of the amino acid was performed from 0 °C to
room temperature over a period of one hour and the final
extraction was performed with ethyl acetate in place of ethyl
ether.
1H-NMR
IS-MS m/e 318 (M-l)
Intermediate PAA-9
Boc-D,L-(8-quinolinyl)glycine.
Method PAA-B
To a stirring solution of Boc-D,L-(8-quinolinyl)glycine
ethyl ester (2.29 g, 6.93 mmol) in 1,4-dioxane (11 mL) was
added a solution of LiOH hydrate (0.32 g, 7.6 mmol) in water.
After 2 h, the solvents were removed in vacuo and the residue
was dissolved in water and washed with diethyl ether. The
aqueous phase was then acidified to pH 3 with solid citric
acid and extracted with ethyl acetate. The organic phase was
then washed with brine, dried with Na2SO4, filtered and
concentrated to give 2.06 g (98%) of the title compound.
1H-NMR
IS-MS, m/e 303.0 (M+l)
Intermediate PAA-10
Boc-D,L-(5-quinolinyl)glycine.
Prepared from Boc-D,L-(5-quinolinyl)glycine ethyl ester
using Method PAA-B.
1H-NMR
IS-MS, m/e 3 03.0 (M+l)
Intermediate PAA-11
Boc-D- (3-bromophenyl)glycine.
Prepared from R-3-bromo-(l-t-butoxycarbonylamino-2-
hydroxyethyl)benzene using Method PAA-C.
Melting Point = 130-132 °C with decomposition
1H NMR (CDCI3)
API-MS, m/e = 286 (M-CO2H+1)
Intermediate PAA-12
Boc-D-(3-methoxycarbonylphenyl)glycine.
Method PAA-C
To a stirred solution of R-3-methoxycarbonyl-(1-t-butoxy-
carbonylamino-2-hydroxyethyl)benzene (338 mg, 1.14 mmol) in
acetone (7.2 mL) was added 5% NaHCO3 (3 mL). The reaction
mixture was cooled to 0 °C. To the stirred suspension was
added KBr (14 mg, 0.12 mmol), TEMPO (181 mg, 1.16 mmol) and
NaOCl dropwise (2.81 mL, 5.25%). After 1 h at 0 °C, TEMPO (136
mg, 0.88 mmol) and NaOCl (1.09 mL; 5.25%) were added. The
reaction was stirred for a further 0.5 h at 0 °C and 5% NaHCO3
(4.3 mL) was added. The reaction was allowed to warm to room
temperature overnight. Acetone was removed under vacuum and
the crude product was partitioned between ethyl acetate and
water. The aqueous layer was washed with ethyl acetate (2x)
and acidified to pH 5 with 10% citric acid and extracted with
ethyl acetate (4x). The combined organic extracts were dried
over MgSO4. Removal of solvent under vacuum gave the product
(305 mg, 86%) .
1H NMR (CDCl3)
API-MS, m/e = 254 (M-C4H9+I)
Intermediate PAA-13
Boc-D-(3-cyanophenyl)glycine.
Prepared from R-3-cyano-(l-t-butoxycarbonylamino-2-
hydroxyethyl)benzene using Method PAA-C.
1H NMR (CDCI3)
API-MS, m/e = 221 (M-C4H9+I)
Intermediate PAA-14
Boc-D-(3-ethanesulfonylaminophenyl)glycine.
To a stirring solution of 3-(ethanesulfonylamino-
phenyl) glycine (20 g, 77.43 nunol) and sodium carbonate (8.2 g,
77.43 mmol) in 3:1 THF:water (200 mL) at 0 °C, was added di-
tert-butyl dicarbonate (18.5 g, 85.17 mmol). After stirring
for 3 0 min, the cold bath was removed; and after an additional
3 0 min at room temperature the solvent was removed; and the
residue was partitioned between ethyl acetate and water. The
aqueous layer was acidified to pH 2 with KHSO4 and extracted
twice with ethyl acetate. The combined ethyl acetate extracts
were washed with water, dried with Na2SO4, filtered and
concentrated in vacuo to give 17.51 g (63%) of a white solid.
1H-NMR
IS-MS, m/e 357.0 (M-l)
Intermediate PAA-15
N-Boc-D,L-(5- thiazolyl) glycine.
To a r.b. flask (150 cm3), was added Boc-D,L-
(5-thiazolyl)glycine ethyl ester (7.00 g, 24.70 mmol) to
ethanol (c.a. 100 cm3) with stirring. 2 M Sodium hydroxide
solution (25 cm3, 50 mmol) was added and allowed to stir for 1
h. Reaction monitored by TLC (60% hexane/ethyl acetate; s.m.
r.f 0.5, prod. r.f. 0.). Reaction concentrated in vacuo and
product taken up in saturated bicarbonate (c.a. 50 cm3) and
washed with ethyl acetate {c.a. 3 0 cm3). Aqueous layer was
acidified to pH 2 with concentrated hydrochloric acid and
product extracted with 3:1 chloroform/isopropanol solution
{c.a. 3x60 cm3). The organic layer was dried over magnesium
sulphate and evaporated to dryness to give an orange solid
(4.47 g, 17.30 mmol) [74% Yield].
lH NMR (CDC13); 1.35 (9H, s), 5.60 (1H; d), 5.83 (1H, d), 7.88
(1H, s), 8.80 (1H, s).
Intermediate PAA-16
N-Boc-D,L-(4-thiazolyl)glycine.
Method PAA-D
To a solution of N-Boc-D,L-(4-thiazolyl)glycine ethyl
ester (0.700 g, 2.470 mmol) in methanol (c.a. 15 cm3), was
added 2 M sodium hydroxide (2.47 cm3, 4.94 0 mmol) and allowed
to stir for 90 min. The solution was concentrated in vacuo and
taken up in water (c.a. 20 cm3). The aqueous solution was
washed with ethyl acetate (c.a. 20 cm3), and then acidified to
pH 2 with 5% hydrochloric acid solution (c.a. 5 0 cm3). The
product was extracted with ethyl acetate (c.a. 3x30 cm3) ,
dried over magnesium sulphate, and concentrated in vacuo to
yield a pale yellow oil (0.582 g, 2.254 mmol) [91% yield].
1H NMR (CDCl3) 1.35 (9H, s) , 5.5 (1H, d) , 5.8 (1H, d) , 7.35
(1H, d) , 8.75 (1H, d) , 9.8-10.2 (1H, br.).
Intermediate PAA-17
N-Boc-D,L-(2-methylthiazol-4-yl)glycine.
Prepared from N-Boc-D,L-(2-methylthiazol-4-yl)glycine
ethyl ester using Method PAA-D.
1H NMR (CDCl3) 1.35 (9H, s), 2.6 (3H, s), 5.4 (1H, d) , 5.9
(1H, s), 7.1 (1H, s).
Intermediate PAA-18
N-Boc-D,L-(2-Benzyloxycarbonylamino-4- thiazolyl) glycine.
Is prepared from D,L-(2-benzyloxycarbonylamino-4-
thiazolyl)glycine. The benzyloxycarbonyl protecting group is
removed from the thiazolyl amino group at a convenient point
in the preparation of a final compound using a conventional
method, such as, for example, heating a solution of an
intermediate in HBr/acetic acid at 60 °C, followed by
evaporation and a conventional isolation, such as by using SCX
ion exchange chromatography.
D,L-(2 -Benzyloxycarbonylamino-4-thiazolyl)glycine.
Was prepared by the method of Hardy, K. ; Harrington, F.
and Stachulski, A. - J. Chem. Soc. Perkin Trans I (1984)
1227-1235.
Intermediate PAA-19
Boc-R-(4-meth6xycarbonylphenyl)glycine.
To a solution of Boc-R-(4-methoxycarbonylphenyl)glycine
methyl ester (692 mg) in THF (10 mL) was added a solution of
lithium hydroxide hydrate (90 mg) in water (7 mL). The
mixture immediately became cloudy and over 15 min cleared.
After 30 min, tlc showed the reaction to be complete. Ethyl
acetate (2 0 mL) and water (20 mL) were added, and the aqueous
layer separated. The aqueous solution was acidified with 2 M
hydrochloric acid and extracted with ethyl acetate (3 x 20
mL) . The organic solution was then washed with water x 2 and
brine x 2, dried with MgSO4 and evaporated to give the mono-
ester (650 mg, 98%), pure by tlc.
l H NMR
Intermediate PAA-20
Boc-R-(4-MethOxyphenyl)glycine.
Boc-R-(4-hydroxyphenyl)glycine methyl ester was converted
to Boc-R-4-methoxyphenylglycine using the alkylation method
described by Basak et al.(Tetrahedron Lett. 1998, 39 (27),
4883-4886), followed by hydrolysis of the methyl ester with
lithium hydroxide in aqueous THF.
1H NMR
Intermediate PAA-21
N-4-Methoxybenzoyl-N-2,4-dimethoxybenzyl-D,L-(2-trifluoro-
methylphenyl)glycine.
Prepared from N-4-methoxybenzoyl-N-2,4-dimethoxybenzyl-
D,L-(2-trifluoromethylphenyl)glycine methyl ester using Method
PAA-B (3 equivalents of LiOH hydrate).
1H NMR
IS-MS, m/e 503.9 (m + 1)
Intermediate PAA-22
N-4-Methoxybenzoyl-N-2, 4-dijnethoxybenzyl-D,L- (thien-2-yl) -
glycine.
Method PAA-E
To a solution of 2-thiopheneboronic acid (5.0 g, 3 9.0
mmol, 1 equiv) in 275 mL of methylene chloride at rt was added
3,4-dimethoxybenzylamine (5.89 mL, 39.0 mmol, 1 equiv)
followed by glyoxylic acid monohydrate 3.6 g, 3 9 mmol, 1
equiv). The reaction was allowed to stir for 56 hours at rt
after which time the resultant precipitate was filtered and
washed with methylene chloride to afford 9.3 g (78%) of N-2,4-
dimethoxybenzyl-D,L-(thien-2-yl) glycine as an off-white solid
(IS-MS, m/e 308 (m + 1) ) .
A portion of the solid (5.0 g, 16.3 mmol, 1 equiv.) was
dissolved in acetone (20 mL) and 1 N sodium hydroxide (20 mL)
at rt. To this solution was simultaneously added anisoyl
chloride (2.78 g, 16.3 mmol, 1 eguiv.) in 20 mL of acetone and
2 N sodium hydroxide in dropwise fashion. After stirring at
rt for 1 h, the reaction was cooled to 0 °C and was acidified
to pH 2-3. Diethyl ether was added and the product was
extracted into the organic phase. The combined organic phases
were washed with brine, dried over sodium sulfate, filtered,
and concentrated to afford 5.1 g (71%) of the titled compound
as a white solid.
IS-MS, m/e 440 (m + 1).
Intermediate PAA-23
N-Boc-N-2,4-dimethoxybenzyl-D,L-(thien-2-yl)glycine.
To a solution of N-2,4-dimethoxybenzyl-D,L-(thien-2-
yDglycine (1.0 g, 3.2 mmol, 1 equiv) in 6 mL of acetone and 6
mL of water at rt was added triethylamine (0.97 mL, 7.0 mmol,
2.1 equiv.) followed by addition of 2.- (tert-butoxy-
carbonyloxyimino)-2-phenylacetonitrile (BOC-ON) (0.76 g, 3.1
mmol, 0.95 equiv). After stirring at rt overnight, the
reaction was diluted with water and washed with ether. The
aqueous phase was then acidified with 0.5 M citric acid and
the product was extracted into diethyl ether. The combined
organic phases were washed with brine, dried over sodium
sulfate, filtered, and concentrated to afford 0.3 5 g (29%) of
the titled compound as a crude yellow oil.
IS-MS, m/e 408 (m +1).
Intermediate PAA-24
Boc-D,L-isoquinolin-8-ylglycine.
Prepared from ethyl Boc-D,L-isoquinolin-8-ylglycine using
Method PAA-B. The product was precipitated from a basic
aqueous solution by adjusting the pH to 3 with solid citric
acid.
1NMR
IS-MS, m/e 303.0 (M+l)
Analysis for C16H18N2O4.0.5 H2O:
Calcd: C, 61.73; H, 6.15; N, 9.00;
Found: C, 61.62; H, 5.66; N, 8.84.
Intermediate PAA-25
Boc-D,L-Naphthalen-1-ylglycine.
Method PAA-F
Part A: D,L-Naphthalen-1-ylglycine hydrochloride.
To a solution of sodium cyanide (10.0 g, 0.22 mmol) in 40
mL of water was added ammonium chloride (11.4 g, 0.22 mmol),
and the mixture was stirred until dissolution was complete. A
solution of 1-naphthaldehyde (31.0 g, 0.22 mmol) in 40 mL of
methanol was then added and the resultant mixture was allowed
to stir at room temperature for two days. An additional 150
mL of water was then added and the crude product was extracted
into EtOAc. The combined organic layers were washed with
water, dried over Na2SO4, filtered and concentrated to afford
a crude oil. The crude residue was chromatographed over
silica gel, eluting with with 10:1 EtOAc :CH2Cl2, to give 35 g
of a light brown oil. This material was then dissolved in 250
mL of 5 N HC1 and was heated to reflux for 9 h. The reaction
was allowed to cool to room temperature and the product was
allowed to crystallize overnight. Filtration of the mixture
afforded 13.6 g (29%) of the title compound as light brown
crystals.
l NMR
IS-MS, m/e 201.9 (M+l)
Part B: Boc-D,L-Naphthalen-l-ylglycine.
To a solution of D,L-naphthalen-1-ylglycine hydrochloride
(13.6 g, 57.2 mmol) and 2 N sodium hydroxide (57 mL, 115 ramol)
in 120 mL of 1,4-dioxane and 60 mL of water was added (Boc)20
(15 g, 69 mmol). The reaction was allowed to stir at room
temperature for 3 h after which time the solution was brought
to pH 5 by addition of 1 N sulfuric acid. The product was
then extracted into EtOAc; and the combined organic extracts
were dried over Na2SO4, filtered, and concentrated to give 14
g (81%) of the title compound as a light brown foam.
1NMR
IS-MS, m/e 300.1 (M-l)
Intermediate PAA-26
Boc-D,L-(2-methylthiophenyl)glycine.
To a solution of 2-(methylthio)benzaldehyde (15 g, 98.7
mmol) in 100 mL of ethanol was added ammonium carbonate (23.1
g, 296 mmol), and a solution of potassium cyanide (12 g, 148
mmol) in 100 mL water. The reaction was heated and stirred at
70 °C for 3 h after which time the reaction was concentrated
under reduced pressure. The product was extracted into ethyl
acetate; and the combined organic phases were washed with
brine, dried over Na2SO4, filtered and concentrated. The
resultant crude residue was taken up in 70 mL of ethyl
acetate, and 70 mL of 5 N sodium hydroxide was added. The
reaction was heated to reflux for three days after which time
the ethyl acetate was removed under reduced pressure. To the
aqueous mixture was sequentially added 100 mL of dioxane,
Boc2O (42 g, 192 mmol), and 100 mL of 2.5 N sodium hydroxide.
The reaction was then heated at reflux for 48 h. After
cooling to room temperature, the reaction was diluted with
water and the aqueous phase was washed with ethyl ether. The
aqueous layer was then acidified to pH 2 and the product was
extracted into ethyl acetate. The combined organic extracts
were washed with brine, dried over MgSO4, filtered, and
concentrated to afford 21.7 g of a crude residue.
Purification by silica gel chromatography (gradient elution,
97:2:1 to 95:4:1 dichloromethane:tnethanol:acetic acid)
provided 5.0 g (17%) of the title compound.
lH-NMR
ES-MS m/e 296 (M-l)
Intermediate PAA-27
Boc-D,L-(2-methylsulfonylpheny1)glycine.
To a solution of boc-D,L-(2-methylthiophenyl)glycine (4.5
g, 15.2 mmol) in 75 mL of methanol was added a solution of
oxone (14 g, 23 mmol) in water. The reaction was stirred at
room temperature for 2 h after which time the methanol was
removed under reduced pressure. The product was extracted
into ethyl acetate and the combined organic layers were washed
with brine, dried over MgSO4, filtered, and concentrated to
afford 4.35 g (87%) of the title compound.
1H-NMR
ES-MS m/e 230(M+I-C5H9O2)
Intermediate PAA-28
Boc-D/L-(benzo[b]thiophen-3-yl)glycine.
May be prepared by the method of Kukolja, s. et al.
J. Med. Chem. 1985, 28, 1886-1896.
Preparation of Intermediates A-l - A-12
The following compounds were prepared according to the
indicated method (Method A-A or Method A-B) from che indicated
starting materials, unless otherwise described.
Intermediate A-l
1-[2-(4-Pyridinyl)ethyl]piperazine hydrochloride.
Method A-A
A. 1-Boc-piperazine (30 g, 285 tnmol) , 4-vinylpyridine (40 g,
216 nunol) and acetic acid (12.9 g, 215 tnmol) were mixed in
ethanol (400 mL) and heated to reflux for 18 h. The mixture
was cooled to room temperature and concentrated under vacuum.
The residue was dissolved in water and ethyl acetate and
neutralized with satd NaHCO3. The layers were separated. The
water layer was extracted with ethyl acetate. The organic
layers were combined, washed with brine, dried (Na2SO4),
filtered and concentrated. The crude product was purified by
SiO2 chromatography to provide l-Boc-4-[2-(4-
pyridinyl)ethyl]piperazine (55.9 g, 87%) as an off white
solid.
1H-NMR(CDC13)
CI-MS, m/e - 292 (M+l)
B. l-Boc-4-[2-(4-pyridinyl)ethyl]piperazine (25 g, 85.8
mmol) was dissolved in methanol (100 mL) and was cooled to
0 °C. Saturated HC1 in methanol (100 mL) was added, and the
mixture allowed to warm to room temperature for 1 h. The
mixture was concentrated under vacuum and provided
1-[2-(4-pyridinyl)ethyl]piperazine hydrochloride (23.8 g, 92%)
as a white solid.
1H-NMR(CD3OD)
CI-MS, m/e = 192 (M+l)
Alternatively, l-Boc-4-[2-(4-pyridinyl)ethyl]piperazine
(1.0 g, 3.43 mmol) was dissolved in ethyl ether. Ethyl
acetate (15 mL) saturated with HC1 was added, and the mixture
stirred for 3 0 min at room temperature. The mixture was
concentrated under vacuum and provided 1-[2-(4-pyridinyl)-
ethyl]piperazine hydrochloride (900 mg, 87%) as a tan solid.
1H-NMR(CD3OD)
CI-MS, m/e = 192 (M+l)
Intermediate A-2
1-[2-(2-Pyridinyl)ethyl]piperazine.
Prepared from Boc-piperazine and 2-vinylpyridine using
Method A-A.
1H-NMR(CD3OD)
CI-MS, m/e = 192 (M+l)
Intermediate A-3
1- [2-(2-Pyrazinyl)ethyl]piperazine.
Prepared from Boc-piperazine and 2-vinylpyrazine using
Method A-A.
1H-NMR (CD3OD)
CI-MS, m/e = 193 (M+l)
Intermediate A-4
1- [2-(3-Pyridazinyl)ethyl]piperazine.
Prepared from Boc-piperazine and 3-vinylpyridazine
(prepared using the method described in J. Chem. Soc., Chem.
Cornnun. 1985, 1632-1633) using Method A-A.
1H NMR (CD3OD)
API-MS, m/e = 193 (M+l)
Intermediate A-5
1- [2-(3-Pyridinyl)ethyl]piperazine.
Method A-B
l-Boc-4-[(3-pyridinyl)acetyl]piperazine (8.0 g, 26.2
mmol) was added to a solution of borane-THF (2.0 M in THF,
39.5 mL, 78.6 mmol) in THF (200 mL) at 0 °C. The mixture was
heated to reflux for 8 h and cooled to room temperature. The
excess borane was quenched with methanol and 3 N HCl. The
mixture stirred for 3 h at room temperature, and the solvents
were removed under vacuum. The crude product was purified by
chromatography (Sio2, 4:1 CH2Cl2:CMA) to provide l-[2-(3-
pyridinyl)ethyl]piperazine (2.82 g, 36%) as a light yellow
oil.
1H NMR (CD3OD)
API-MS, m/e = 192 (M+l)
Intermediate A-6
1-[2-(4-Imidazolyl)ethyl]piperazine.
Prepared from l-Boc-4-[(4-imidazolyl)acetyl]piperazine
using Method A-B.
1H-NMR
IS-MS, m/e 181.2 (M+l)
Intermediate A-7
1-[2-(1-Imidazolyl)ethyl]piperazine.
Prepared from l-Boc-4-[(1-imidazolyl)acetyl]piperazine
using Method A-B.
1H-NMR
IS-MS, m/e 181.4 (M+l)
Intermediate A-8
1-[2-(1-Pyrazolyl)ethyl]piperazine.
Prepared from l-Boc-4-[(1-pyrazolyl)acetylpiperazine
using Method A-B.
1H-NMR
IS-MS, m/e 181.4 (M+l)
Intermediate A-9
1-(2-Thiazol-2-ylethyl)piperazine.
A. A solution of Boc2O (26 g, 120 mmol) in methylene
chloride (50 mL) was slowly added to a solution of ethyl
piperazin-1-ylacetate (20 g, 116 mmol) in CH2Cl2 (500 mL) .
The mixture was stirred for 1 h at room temperature. The
solvent was removed under vacuum to provide ethyl 4-Boc-
piperazin-1-ylacetate (31.9 g, 100%) as a white solid.
1H NMR (CDCI3) .
CI-MS, m/e = 273 (M+l).
B. N-Methoxy-N-methylamine hydrochloride (4.3 g, 44.1 mmol)
was dissolved in methylene chloride (25 mL). The solution was
cooled to -78 °C, and a solution of trimethylaluminum (44.1
mL, 44.1 mmol, 1 M in heptane) was slowly added. The mixture
was stirred at 0 °C for 3 0 min and was allowed to warm to room
temperature and stirred for 3 0 min. The mixture was then
cooled to 0 °C, and a solution of ethyl 4-Boc-piperazin-l-
ylacetate (10 g, 36.8 mmol) was added dropwise. After 15 min,
the cold bath was removed and stirring continued overnight.
The mixture was diluted with ethyl acetate and water. The
layers were separated, and the water layer extracted with
ethyl acetate. The organic layers were combined, washed with
brine, dried (Na2SO4), filtered, and concentrated to provide
N-methoxy-N-methyl-4-Boc-piperazin-l-ylacetamide as a light
yellow oil (6.02 g, 57%) that solidified upon standing. The
product was used without further purification.
1H NMR (CDCI3).
CI-MS, m/e = 288 (M+l) .
C. n-Butyl lithium (1 M in hexanes, 12.2 mL, 12.2 mmol) was
slowly added to a solution of 2-bromothiazole (2.0 g, 12.2
mmol) in diethyl ether (50 mL) at -78 °C. The mixture stirred
at -78 °C for 1 h. Then, a solution of N-methoxy-N-methyl-4-
Boc-piperazin-1-ylacetamide (3.0 g, 10.4 mmol) in
tetrahydrofuran was slowly added. The mixture was allowed to
slowly warm to -2 0 °C and stirred for 4 h. The mixture was
then diluted with water followed by ethyl acetate. The water
layer was extracted with ethyl acetate and the organic layers
were combined, washed with brine, dried (Na2SO4) , filtered,+
and concentrated. The crude product was purified by-
chroma tography (SiO2 20:1 - 6:1 CH2C12:CMA) to provide 1-Boc-
4-(2-oxo-2-thiazol-2-ylethyl)piperazine (2.2 g, 68%) as a
colorless oil.
1h NMR (CDC13).
CI-MS, m/e = 312 (M+l).
D. l-Boc-4- (2-oxo-2-thiazol-2-ylethyl)piperazine (5.0 g,
16.1 mraol) was dissolved in methanol (25 mL) . To this
solution, magnesium sulfate (2 g) was added, followed by
p-tosylhydrazine (3.9 g, 20.2 mtnol) . The mixture was stirred
for 48 h and then filtered, and the filtrate concentrated
under vacuum. The residue (6.0 g, about 12 mmol) was
redissolved in methanol (120 mL) , and sodium
triacetoxyborohydride (10.1 g, 48 mmol) was added. The
mixture was heated to reflux overnight. The mixture was
cooled to 0 °C and concentrated HC1 (15 mL) slowly added. The
mixture was allowed to warm to room temperature and stirred
for 1 h. The mixture was concentrated to half the volume and
placed on an SCX column (3 0 g, pretreated with 5% acetic acid
in methanol) and washed with methanol (500 mL) . The product
was eluted with saturated ammonium hydroxide in methanol (500
mL) and the solvent removed under vacuum. The crude product
was then purified by chroma tography (SiC>2, 12:1 - 4:1
CH2C12:CMA) to provide 1-(2-thiazol-2-ylethyl)piperazine (1.9
g, 57%).
1H NMR (CDCI3).
CI-MS, m/e = 198 (M+l).
Intermediate A-10
1-[2-(2-Benzyloxycarbonylaminothiazol-4-yl)ethyl] piperazine
Hydrochloride.
Using methods substantially equivalent to those described
in Method A-B, the title compound was prepared from l-Boc-4-
[2- (2-benzyloxycarbonylaminothiazol-4-yl) acetyljpiperazine
(85%) .
1H NMR (CD3OD).
CI-MS, m/e = 347 (M+l).
Intermediate A-11
1- [2- (3-Fluoropyridin-4-yl)ethyl]piperazine Trihydrochloride.
A. n-Butyl lithium (1.8 M in hexanes, 35 mL, 64.4 mmol) was
charged to a round bottom flask and diluted with THF (25 mL) .
The solution was cooled to 0 °C, and a solution of N,N-
diisopropylamine (9.0 mL, 65 mmol) in THF (25 mL) was slowly
added. The mixture was stirred at 0 °C for 20 min and was
cooled to -78 °C. A solution of 3-fluoropyridine (20 g, 206
mmol) was added dropwise (temperature of mixture kept below -
70 °C) , resulting in the formation of a red precipitate. The
mixture was stirred at -78 °C for 4 h. Ethylene oxide (4.6 M
in THF, 67.2 mL, 309 mmol) was slowly added, and the mixture
allowed to warm to room temperature overnight. The mixture
was diluted with water and CH2Cl2. The layers were separated,
and the water layer extracted with CH2Cl2. The organic layers
were combined, washed with brine, dried (Na2SO4) , filtered,
and concentrated to provide a dark brown oil. The residue was
purified by chromatography (SiO2, 19:1 - 6:1 CH2Cl2:CMA) to
provide 3-fluoro-4-(2-hydroxyethyl) pyridine (6.7 g, 23%) as a
tan oil.
1H NMR (CDCI3) .
CI-MS, m/e = 142 (M+l) .
B. 3-Fluoro-4-(2-hydroxyethyl)pyridine (4.0 g, 2 8.3 mmol)
and triethylamine (8.3 mL, 60 mmol) were dissolved in CH2Cl2
(40 mL) and cooled to 0 °C. To this solution, methanesulfonyl
chloride (2.0 mL, 31.2 mmol) was added dropwise. The mixture
stirred at 0 °C for 1 h. The mixture was diluted with water,
and the layers separated. The water layer was extracted with
CH2Cl2. The organic layers were combined, washed with brine,
dried (Na2SO4), filtered, and concentrated under vacuum to
provide 3-fluoro-4- (2-methanesulfonyloxyethyl)pyridine (5.2 g,
83%) as a pink oil.
1H NMR (CDCI3) .
CI-MS, m/e = 220 (M+l) .
C. 3-Fluoro-4- (2-methanesulf onyloxyethyDpyridine (5.2 g,
23.7 mmol) was dissolved in DMF (65 mL) . 1-Boc-piperazine
(8.85 g, 47.4 mmol), K2CO3 (3.3 g, 23.7 mmol), Nal (3.6 g,
23.7 mmol) and CS2CO3 (7.7 g, 23.7 mmol) were added, and the
mixture heated to 55 °C for 18 h. The mixture was cooled to
room temperature and diluted with water and ethyl acetate.
The layers were separated, and the water layer extracted with
ethyl acetate. The organic layers were combined, washed with
brine, dried (Na2SO4), filtered, and concentrated under vacuum
to provide a solution of product and DMF. The residue was
dissolved in diethyl ether and water. The layers were
separated, and the water layer extracted with diethyl ether.
The organic layers were combined, washed with brine, dried
(Na2SO4) , filtered, and concentrated under vacuum. The crude
product was purified by chromatography (SiC>2, 15:1 - 6:1
CH2C12:CMA) to give l-Boc-4-[2-(3-fluoropyridin-4-
yl)ethyl]piperazine (6.2 g, 84%).
1H NMR (CDCI3)•
CI-MS, m/e = 310 (M+l).
D. l-Boc-4-[2-(3-fluoropyridin-4-yl)ethyl]piperazine (6.0 g,
19.4 mmol) was dissolved in methanol (2 0 mL) and anisole (6
mL) . To this solution, concentrated hydrochloric acid (15 mL)
was added and the mixture stirred for 1 h. The solvents were
removed under vacuum to provide a yellow solid. The residue
was suspended in diethyl ether and sonicated for 1 h. The
product was recovered by vacuum filtration, and the solid
dried under vacuum to provide 1-[2-(3-fluoropyridin-4-
yl)ethyl]piperazine trihydrochloride (5.2 g, 84%) as an off
white solid.
1h NMR (CD3OD).
CI-MS, m/e = 210 (C11H16FN3 + 1).
Intermediate A-12
1-[2-(2-Cyanopyridin-4-yl)ethyl] piperazine.
A. Ethyl 4-pyridylacetate (20 g, 121 mmol) was added to a
suspension of LiAlH4 (9.2 g, 242 mmol) in diethyl ether (600
mL) . Diatomaceous earth (about 50 tnL) was added to aid
stirring. The mixture stirred overnight. The mixture was
cooled to 0 ;°C and aqueous NaOH (15%) was added until
degassing ceased. The mixture was allowed to stir for 1 h.
The solids were removed by filtration and the filtrate was
concentrated under vacuum. The crude product was purified by
chromatography (SiO2, 40:1 - 20:1 CH2Cl2:methanol) to provide
4-(2-hydroxyethyl)pyridine (8.1 g, 54%) as an amber liquid.
1H NMR (CDCl3).
CI-MS, m/e = 124 (M+l).
B. 4- (2-Hydroxyethyl)pyridine (8.1 g, 65.8 tnmol) and
triethylamine (10.1 mL, 66 mmol) were dissolved in CH2C12 (100
mL) and cooled to -78 °C. To this solution, tert-butyl-
dimethylsilyl chloride (11.0 g, 66 mmol) was added. The
mixture was allowed to warm to room temperature overnight.
The mixture was placed directly on a bed of SiO2 and eluted
with 100:0 - 10:1 CH2Cl2:methanol to provide 4-[2-(tert-
Butyldimethylsilyloxy)ethyl] pyridine (15.3 g,. 97%).
1H NMR (CDCl3).
CI-MS, m/e = 238 (M+l).
C. 4-[2-(tert-Butyldimethylsilyloxy)ethyl]pyridine (15.2 g,
64 mmol) was dissolved in CH2Cl2 (200 mL). To this solution,
m-chloroperbenzoic acid was added and the solution stirred at
room temperature for 72 h. The solution was washed with
aqueous NaOH (1 m) and layers separated. The water layer was
extracted with CH2Cl2. The organic layers were combined,
dried (K2CO3), filtered and concentrated under vacuum to
provide 4-[2-(tert-butyldimethylsilyloxy)ethyl]pyridine-W-
oxide (13.4 g, 83%).
1H NMR (CDCl3).
CI-MS, m/e = 254 (M+l).
D. 4-[2-(tert-Butyldimethylsilyloxy)ethyl]pyridine-N- oxide
(13.4 g, 52.9 mmol) was dissolved in triethylamine (14.8 mL,
105 mmol). Trimethylsilyl cyanide (28.4 mL, 212 mmol) was
added and the mixture heated to 90 °C for 3 h. The mixture
was allowed to cool to room temperature and stand overnight.
The mixture was partitioned between water and CH2Cl2. The
layers were separated and water layer extracted with CH2Cl2
The organic layers were combined, washed with water and brine,
dried (K2CO3), filtered and concentrated to provide a dark oil
(14 g) . The residue was purified by chromatography (SiO2,
40:1 CH2Cl2:ethyl acetate) to provide 4-[2-(tert-butyl-
dimethylsilyloxy)ethyl]-2-cyanopyridine (12.8 g, 92%) as a
yellow oil.
1h NMR (CDCl3).
CI-MS, m/e = 263 (M+l).
E. 4-[2-(tert-Butyldimethylsilyloxy)ethyl]-2-cyanopyridine
(12.8 g, 48.8 mmol) and a solution of tetrabutylammonium
fluoride (1 M in THF, 73 mL, 73 mmol) were charged to a round
bottom flask and stirred at room temperature overnight. The
mixture was diluted with water and ethyl acetate. The layers
were separated and the water layer extracted with ethyl
acetate. The organic layers were combined, washed with water
and brine, dried (Na2S04), filtered and concentrated. The
residue was purified by chromatography (SiO2, 50:1 CH2Cl2:
methanol) to provide 2-cyano-4-(2-hydroxyethyl)pyridine (4.4
g, 61%) as an off white solid.
lH NMR (CDC13) .
CI-MS, m/e = 149 (M+l).
F. 2-Cyano-4-(2-hydroxyethyl)pyridine (4.3 g, 29 mmol) was
dissolved in pyridine (2.85 mL, 34.8 mmol.) and CH2Cl2 (40 mL)
and cooled to 0 °c. To this solution, benzenesulfonyl
chloride (4.5 mL, 34.8 mmol) was added and the mixture allowed
to stir at room temperature overnight. The solvent was
removed under vacuum and the residue was purified by
chroma tography (SiO2, 20:1 CH2Cl2: ethyl acetate) to provide a
2:1 mixture of 2-cyano-4-[2-(benzenesulfonyloxy) ethyl] pyridine
and 2-cyano-4-(2-chloroethyl)pyridine (6.0 g, 84%).
1H NMR (CDCl3).
CI-MS, m/e = 167 (CaH7ClN2+l) and 289 (C14H12N2O3S+1).
G. 1-Boc-piperazine (6.8 g, 36 mmol), NaI (2.7 g, 18 mmol),
K2CO3 (3.0 g, 21.6 mmol) and a mixture of 2-cyano-4-[2-
(benzenesulfonyloxy)ethyl]pyridine and 2-cyano-4-(2-chloro-
ethyl )pyridine (2:1, 4.5 g, 18 mmol) was dissolved in DMF (50
mL) and heated to 80 °C overnight. The mixture was allowed to
cool to room temperature and diluted with water and ethyl
acetate. The layers were separated and the water layer
extracted with ethyl acetate. The organic layers were
combined, washed with water and brine, dried (Na2SO4) ,
filtered and concentrated under vacuum to proved a dark oil
(6.0 g). The crude product was purified by chromatography
(SiO2, 1000:10:1 - 2 00:10:1 CH2Cl2:methanol: concentrated
ammonium hydroxide) to provide l-Boc-4-[2-(2-cyanopyridin-4-
yl)ethyl]piperazine (4.0 g, 70%).
1H NMR (CDCI3)•
TLC Rf = 0.5 (200:10:1 CH2Cl2 methanol: concentrated ammonium
hydroxide).
H. l-Boc-4- [2- (2-cyanopyridin-4-yl)ethyl]piperazine (4.0 g,
12.64 mmol) was dissolved in methanol (60 mL) and cooled to 0
°C. Concentrated hydrochloric acid (10.4 mL, 126 mmol) was
added and the mixture stirred for 1 h. The solvents were
removed under vacuum and co-evaporated twice with methanol, a
1:1 mixture of methanol/toluene, and finally with methanol.
The residue was dried under vacuum overnight to provide crude
product (4.5 g) . Half of the product was dissolved in
methanol, concentrated ammonium hydroxide was added, and
solvents were removed under vacuum. The residue was purified
by chromatography (SiO2, 100:10:1 CH2C12:methanol:concentrated
ammonium hydroxide) to provide 1-[2-(2-cyanopyridin-4-
yl)ethyl]piperazine (1.05 g, 69%).
1H NMR (CDCI3) .
CI-MS, m/e = 217 (M+l).
Preparation of Intermediates B-l - B-5
The following compounds were prepared according to the
indicated method (Method B-A, Method B-B or Method B-C) from
the indicated starting materials, unless otherwise described.
Intermediate B-l
l-Boc-4-[(3-pyridinyl)acetyl]piperazine.
Method B-A
1-Boc-piperazine (12 g, 64 mmol), 3-pyridylacetic acid
(8.85 g, 64 mmol), and HOBt (8.64 g, 64 mmol) were dissolved
in DMF. To this solution, EDCI (14.7 g, 76.8 mmol) was added
in portions. The mixture became homogenous and was stirred
for 3 h. The mixture was diluted with water and ethyl
acetate. The layers were separated, and the aqueous layer
extracted with ethyl acetate. The organic layers were washed
with water and brine, dried (Na2SO4), filtered, and
concentrated to provide a yellow solid. The crude product was
purified by recrystallization from hexanes:dichloromethane to
provide l-Boc-4- [(3-pyridinyl)acetyl]piperazine (13.5 g, 69%)
as a white solid.
1H-NMR(CDCl3)
CI-MS, m/e = 306 (M+l)
Intermediate B-2
l-Boc-4- [ (imidazol-4-yl) acetyllpiperazine.
Method B-B
To a stirring suspension of sodium 4-imidazolylacetate
(0.5 g, 3.4 mmol) in DMF (25 mL) was added diethyl cyano-
phosphonate (0.6 mL, 4 mmol). After 5 min, Boc-piperazine
(0.57 g, 3.1 mmol) was added, followed by a solution of'
triethylamine (0.47 mL, 3.4 mmol) in DMF (20 mL). After 72 h,
the solvent was removed in vacuo and the residue was dissolved
in ethyl acetate and washed with satd aq. NaHCO3 and brine,
dried with MgSO4, filtered and concentrated to give 0.95 g of
pink oil.
1H-NMR
IS-MS, m/e 295.1 (M+l)
Intermediate B-3
l-Boc-4-[(1-imidazolyl)acetyl] piperazine .
Preparation of Starting Materials:
l-Boc-4-bromoacetylpiperazine.
To a stirring solution of bromoacetyl bromide (29.8 g,
148 mmol) in THF (250 mL) at 0 °C was added via an addition
funnel a solution of Boc-piperazine (25 g, 134 mmol) and
triethylamine (14.9 g, 148 mmol) in THF (75 mL). After 1 h, a
few grams of ice were added and the mixture was diluted with
ethyl acetate and cold water. The layers were separated and
the organic phase was washed with 1 M aq. citric acid, brine,
satd aq. NaHCO3 and again with brine. The organic phase was
then dried with MgSO4, filtered, and concentrated in vacuo to
give 3 8.2 g (93%) of an off-white powder.
1H-NMR
IS-MS, m/e 251.3 (M-C4H9+1)
Method B-C
To a stirring suspension of NaH (60% dispersion in
mineral oil, 2.34 g, 59 mmol) in THF (75 mL) was added
imidazole (1.46 g, 22 mmol) in small portions. After complete
addition and complete gas evolution, a solution of l-Boc-4-
(bromoacetyl)piperazine (6 g, 19.5 mmol) in THF (40 mL) was
added via an addition funnel. After 2 h, the reaction was
quenched with the slow addition of water and then diluted with
ethyl acetate. The organic phase was washed with satd aq.
NaHCO3, followed by brine, then dried with MgSO4, filtered and
concentrated in vacuo. The residue was suspended in diethyl
ether with sonication, then filtered and dried to give 4.64 g
(81%) of an off white powder.
1H-NMR
IS-MS, m/e 295.2 (M+l)
Intermediate B-4
l-Boc-4-[(1-pyrazolyl)acetyl]piperazine.
Prepared from pyrazole and l-Boc-4-bromoacetylpiperazine
using Method B-C.
1H-NMR
IS-MS, m/e 295.1 (M+l)
Intermediate B-5
l-Boc-4-[(2-Benzyloxycarbonylamino)thiazol-4-ylacetyl] -
piperazine.
A. (2-Aminothiazol-4-yl) acetic acid (10 g, 63.2 mmol) was
dissolved in 1,4-dioxane (100 mL) and aqueous NaOH (6 M, 100
mL), and the solution was cooled to 0 °C. Benzyl chloro-
formate (20 mL, 82.2 mmol) was added, and the mixture was
stirred at room temperature overnight. The mixture was
diluted with diethyl ether, and the layers separated. The
water layer was cooled to 0 °C, and the pH adjusted to
approximately 4 with aqueous HCl (6 M) . The white precipitate
formed was collected by vacuum filtration, washed with water
and diethyl ether, and dried under vacuum to provide (2-
benzyloxycarbonylaminothiazol-4-yl)acetic acid (7.5 g, 41%).
1H NMR (DMSO-dg) .
CI-MS, m/e = 293 (M+l).
B. Using methods substantially equivalent to those described
in Method B-A, the title compound was prepared from (2-
benzyloxycarbonylaminothiazol-4-yl) acetic acid and 1-Boc-
piperazine (95%).
lH NMR (CDC13).
CI-MS, m/e = 461 (M+l).
Preparation of Intermediates C-l - C-28
The following compounds were prepared according to the
indicated method (Method C-A, Method C-B, Method C-C or Method
C-D) from the indicated starting materials, unless otherwise
described.
Intermediate C-l
1- (Boc-D-Phenylglycinyl)-4-[2-(4-pyridinyl) ethyl] piperazine .
Method C-A
D-Boc-Phenylglycine (8.4 g, 33.3 mmol) and
1-[2-(4-pyridinyl)ethyl]piperazine hydrochloride (10 g, 33.3
mmol) were dissolved in DMF (500 tnL) and cooled to
approximately -15 °C in an ice-methanol bath. Diethyl
cyanophosphonate (5.5 mL? 36.6 mmol) was slowly added to the
mixture. Triethylamine (18.6 mL, 133.2 mmol) was added
dropwise to the solution. The mixture was stirred at -15 °C
for 2 h and was allowed to gradually warm to- room temperature
overnight. The mixture was diluted with ethyl acetate and
water. The layers were separated, and the water layer
extracted with ethyl acetate. The organic layers were
combined, washed with brine, dried (Na2SO4), filtered, and
concentrated under vacuum. The crude product was filtered
through a plug of silica gel (1.2 kg) using 1:1 hexanes:ethyl
acetate as eluent to provide 1-(Boc-D-phenylglycinyl)-4-[2-(4-
pyridinyl)ethyl]piperazine (10.6 g, 75%) as a light yellow
oil.
1H-NMR (CDC13)
CI-MS, m/e = 425 (M+l)
Intermediate C-2
1-(Boc-D-Phenylglycinyl)-4-[2-(2-pyridinyl)ethyl]piperazine.
Prepared from Boc-D-phenylglycine and 1-[2-(2-pyridinyl)-
ethyl]piperazine using Method C-A.
1H-NMR(CDCl3)
CI-MS, m/e = 425 (M+l)
Intermediate C-3
1-(Boc-D-Phenylglycinyl)-4-[2-(2-pyrazinyl)ethyl]piperazine.
Prepared from Boc-D-phenylglycine and 1-[2-(2-pyrazinyl)-
ethyl]piperazine using Method C-A.
1H-NMR(CDC13)
CI-MS, m/e = 426 (M+l)
Intermediate C-4
1- (Boc-D-Phenylglycinyl) -4- [2- (3-pyridazinyl) ethyl]piperazine.
Prepared from Boc-D-phenylglycine and 1-[2-(3-pyrid-
azinyl) ethyl] piperazine using Method C-A.
1H NMR (CDC13)
TLC Rf=0.65 (100:10:1 CH2C12:MeOH:NH4OH, SiO2, Analtech No.
02521)
Intermediate C-5
1- (Boc-D-Phenylglycinyl)-4-[2-(3-pyridinyl)ethyl]piperazine.
Prepared from Boc-D-phenylglycine and 1-[2-(3-pyridinyl)-
ethyl]piperazine using Method C-A.
1H-NMR(CDC13)
CI-MS, m/e = 425 (M+l)
Intermediate C-6
1-(Boc-D-Phenylglycinyl)-4-[2-(4-imidazolyl)ethyl]piperazine
Prepared from Boc-D-phenylglycine and 1-[2-(4-imidazol-
yl)ethyl]piperazine using Method C-A.
1H-NMR
IS-MS, m/e 414.2 (M+l)
Intermediate C-7
1-(Boc-D-Phenylglycinyl)-4-[2-(4-pyrazolyl)ethyl]piperazine.
Prepared from Boc-D-phenylglycine and 1-[2-(4-pyrazolyl)-
ethyl]piperazine using Method C-A.
1H-NMR
IS-MS, m/e 414.2 (M+l)
Intermediate C-8
1-(Boc-D-Phenylglycinyl)-4-[2-(1-imidazolyl)ethyl]piperazine.
Prepared from Boc-D-phenylglycine and 1-[2-(1-imid-
azolyl)ethyl]piperazine using Method C-A.
1H-NMR
IS-MS, m/e 414.2 (M+l)
Intermediate C-9
1-(Boc-D-Phenylglycinyl)-4-[2-(1-pyrazolyl)ethyl]piperazine.
Prepared from Boc-D-phenylglycine and 1-[2-(1-pyrazolyl) -
ethyl]piperazine using Method C-A.
1H-NMR
IS-MS, m/e 414.2 (M+l)
Intermediate C-10
1-[Boc-D,L-(Pyridin-2-yl)glycinyl]-4-[2-(4-pyridinyl)ethyl]-
piperazine.
Method C-B
To a stirring solution of ethyl Boc-D,L-(pyridin-2-yl)-
glycine (16.3 g, 58.2 tnmol) in 1,4-dioxane (100 mL) was added
a solution of LiOH hydrate (2.68 g, 64 mmol) in water (100
mL). After 2 h, another solution of LiOH hydrate (1.34 g, 32
mmol) in water (50 mL) was added. After another 2 h, the
solvent was evaporated in vacuo to give 13.56 g of off-white
solid.
A portion of the solid (3 g, 11.6 mmol) was dissolved in
DMF (75 mL) and cooled to 0 °C. To this solution was added
diethyl cyanophosphonate (2.3 g, 13.9 mmol),
N,N-diisopropylethylamine (6 g, 46.4 mmol) and then
1-[2-(4-pyridyl)ethyl]piperazine hydrochloride (3.8 g, 12.8
mmol) , and the reaction was allowed to slowly warm to room
temperature overnight. The next morning, the solvents were
removed in vacuo and the residue was dissolved in ethyl
acetate and washed with satd ag. NaHCO3 and brine, then dried
with Na2SO4, filtered, and concentrated in vacuo. The residue
was then dissolved in a minimal volume of dichloromethane and
chromatographed over silica gel, eluting with a step gradient
of 2% through 10% methanol (with 2 N NH3) in dichloromethane.
The product containing fractions were combined and
concentrated in vacuo to give 2.31 g (47%) of an off-white
foam.
1H-NMR
IS-MS, m/e 426.3 (M+l)
Intermediate C-ll
1-[Boc-D,L-(2-Methoxyphenyl)glycinyl]-4-[2-(4-pyridinyl)-
ethyl]piperazine.
Method C-C
To a stirring solution of Boc-D,L-(2-methoxyphenyl)-
glycine (2 g, 7.1 mmol) and 1-[2-(4-pyridinyl)ethyl]piperazine
trihydrochloride (2.4 g, 7.8 mmol) in DMP (50 mL), was added
HOBt (1.06 g, 7.8 mmol), and triethylamine (4.96 mL, 35.6
mmol) followed by DCC (1.61 g, 7.8 mmol). After stirring
overnight at room temperature, the mixture was filtered; and
the filtrate was concentrated in vacuo. The residue was
dissolved in ethyl acetate and washed with satd aq. NaHCO3
followed by brine, then dried with MgSO4, filtered and
concentrated in vacuo. The residue was then dissolved in a
minimum amount of dichloromethane and chromatographed over
silica gel, eluting with a step gradient of dichloromethane
through 10% (2 N NH3/methanol) in dichloromethane. The
product containing fractions were combined and concentrated in
vacuo to give 2.5 g (77%) of the title compound.
1H-NMR
IS-MS, m/e 455.1 (M+l)
Intermediate C-12
1-(Boc-D-Phenylglycinyl)-4-[2-(thiazol-2-yl)ethyl]piperazine.
Prepared from 1-[2-(thiazol-2-yl)ethyl)piperazine
dihydrochloride and Boc-D-phenylglycine using Method C-A,
except using dichloromethane in place of DMF (80%).
1H NMR (CDCl3).
CI-MS, m/e = 431 (C22H30N4O3S+I).
Intermediate C-13
- 1-(Boc-D-Phenylglycinyl)-4- C2-(2-benzyloxycarbonylamino-
thiaizol-4-yl)ethyl]piperazine.
Prepared from l-[2-(2-benzyloxycarbonylaminothiazol-4-
yl)ethyl]piperazine hydrochloride and Boc-D-phenylglycine
using Method C-A (76%).
1H NMR (CDCl3).
APCI-MS, m/e = 580 (M+l).
Intermediate C-14
1- (Boc-D-Phenylglycinyl)-4-[2-(3-fluoropyridin-4-yl)ethyl]-
piperazine.
Prepared from 1-(Boc-D-phenylglycinyl)-4-[2-(3-fluoro-
pyridin-4-yl) ethyl]piperazine using Method C-A, except using
N,N-diisopropylethylamine in place of triethylamine and
dichloromethane in place of DMF (89%) .
1H NMR (CDCl3) .
APCI-MS, m/e = 443 (M+l).
Intermediate C-15
1- (Boc-D-Phenylglycinyl)-4-[2-(2-cyanopyridin-4-yl)ethyl]-
piperazine.
Method C-D
1-[2-(2-cyanopyridin-4-yl)ethyl] piperidine (1.0 g, 4.6
mmol) and Boc-D-phenylglycine (1.39 g, 4.63 mmol) were
dissolved in CH2Cl2 (20 mL) and cooled to -10 °C. To this
solution, diethyl cyanophosphonate (0.94 mL, 4.63 mmol) was
added, followed by a solution of triethylamine (0.97 mL, 6.9
mmol) in CH2Cl2 (10 mL). The mixture was allowed to slowly
warm to room temperature overnight. The mixture was diluted
with water and the layers separated. The water layer was
extracted with CH2Cl2. The organic layers were combined,
washed with brine, dried (Na2SO4), filtered and concentrated
under vacuum to provide crude product (3.0 g). The crude
product was purified by chromatography (SiO2, 1000:10:1 -
400:10:1 CH2Cl2:methanol:concentrated ammonium hydroxide) to
provide 1-(Boc-D-phenylglycinyl)-4-[2-(2-cyanopyridin-4-yl)-
ethyl]piperazine (1.61 g, 78%).
lH NMR (CDCl3) .
CI-MS, m/e = 450 (M+l).
Intermediate C-16
1- [Boc-D/L-(2-Chlorophenyl)glycinyl]-4-(l-methylpiperidin-4-
yl)piperazine.
Prepared from Boc-D,L-(2-chlorophenyl) glycine and 1-(1-
methylpiperidin-4-yl)piperazine using Method C-C, with EDCI in
place of DCC and HOAt in place of HOBt.
1H NMR
IS-MS, m/e 451.0 (M+l)
Intermediate C-17
1- [Boc-D,L-(Quinolin-8-yl)glycinyl]-4-(l-methylpiperidin-4-
yl)piperazine.
Prepared from Boc-D,L-(quinolin-8-yl) glycine and 1-(1-
methylpiperidin-4-yl)piperazine using Method C-C, with EDCI in
place of DCC and HOAt in place of HOBt.
1H NMR
Intermediate C-18
1- [Boc-D,L-(2-Trifluoromethylphenyl)glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine.
Prepared from Boc-D,L-(2-trifluoromethylphenyl)glycine
and 1-(1-methylpiperidin-4-yl)piperazine using Method C-C,
with DIEA in place of TEA.
1H NMR
IS-MS, m/e 485.0 (M+l)
Intermediate C-19
1- [Boc-D-Cyclopentylglycinyl]-4-(l-methylpiperidin-4-yl)-
piperazine.
Prepared from Boc-D-cyclopentylglycine and 1-(1-methyl-
piperidin-4-yl)piperazine using Method C-C, with EDCI in place
of DCC and HOAt in place of HOBt.
1H NMR
IS-MS, m/e 409.3 (M+l)
Intermediate C-20
1-[Boc-D-Cyclohexylglycinyl]-4-(l-methylpiperidin-4-yl)-
piperazine.
Prepared from Boc-D-cyclohexylglycine and 1-(1-methyl-
piperidin-4-yl)piperazine using Method C-C, with EDCI in place
of DCC and HOAt in place of HOBt.
1H NMR
IS-MS, m/e 423.3 (M+l)
Intermediate C-21
1-[Cbz-D-Phenylglycinyl]-4-(2-phenethyl)piperazine.
Prepared from 4-(Cbz-D-phenylglycinyl)piperazine and
phenylacetaldehyde using Method I-A, with sodium triacetoxy-
borohydride in place of sodium cyanoborohydride and
dichloroethane in place of methanol (71%).
1H NMR (CDC13).
APCI-MS, m/e = 458 (M+l).
Intermediate C-22
1-[Boc-D,L-(thiazol-2-yl)glycinyl]-4-(l-methylpiperidin-4-yl)-
piperazine.
Prepared from ethyl Boc-D,L-thiazol-2-ylglycine and 1-(1-
methylpiperidin-4-yl)piperazine using Method C-B.
IS-MS, m/e 424.0 (M+1)
Intermediate C-23
1-[Boc-D,L-(Benzo[b]thiophen-3-yl)glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine.
Prepared from Boc-D,L-(benzo[b]thiophen-3-yl)glycine and
1-(l-methylpiperidin-4-yl)piperazine using Method C-C,
substituting EDCI for DCC, N,N-diisopropylamine for
triethylamine, and substituting dichloromethane for DMF.
1H-NMR
LCMS m/z 473.4 (M+l)
Intermediate C-24
1- [Boc-D,L-(Naphthalen-1-yl)glycinyl]-4-(l-methylpiperidin-4-
yl)piperazine.
Prepared from Boc-D,L-naphthalen-l-ylglycine and 1-(1-
methylpiperidin-4-yl)piperazine using Method C-C, substituting
EDCI for DCC and substituting N,N-diisopropylamine for
triethylamine.
1H-NMR
IS-MS, m/e 467.1 (M+l)
Intermediate C-25
1-[Boc-D,L-(2-Methylsulfonylphenyl)glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine.
Prepared from Boc-D,L-(2-methylsulfonylphenyl)glycine and
1-(l-methylpiperidin-4-yl)piperazine using Method C-C,
substituting EDCI/HOAt for DCC/HOBt and substituting
N,N-diisopropylethylamine for triethylamine.
1H-NMR
IS-MS, m/e 495 (M+l)
Analysis for C24H38N4O5S:
Calcd: C, 58.27; H, 7.74; N, 11.32;
Found: C, 58.05; H, 7.63; N, 11.43.
Intermediate C-26
1- [Boc-D,L-Thiazol-5-ylglycinyl]-4-[2-(pyridin-4-yl)ethyl]-
piperazine.
To a solution of Boc-D,L-thiazol-5.-ylglycine (1.33 g,
5.15 mmol), HOAt (772 mg, 5.67 mmol), 1-[2-(pyridin-4-yl)-
ethyl]piperazine dihydrochloride (1.55 g, 5.15 mmol) and
triethylamine (1.58 mL, 11.3 mmol) in DMF (41 mL) was added
EDCI (1.09 g, 5.67 mmol), and the mixture stirred at room
temperature for 18 h. The solvent was removed in vacua, the
residues taken up in chloroform: isopropyl alcohol (2:1) and
washed with water, satd aqueous sodium bicarbonate, dried
(MgSO4) and concentrated in vacuo to an orange-brown oil. The
crude reaction product thus obtained was carried on to the
next step without further purification.
Intermediate C-27
1- [Boc-D,L-(2-Methylthiazol-4-yl)glycinyl]-4-[2-(pyridin-4-
yl)ethyl]piperazine.
Prepared from Boc-D,L-(2-methylthiazol-4-yl)glycine and
1-[2-(pyridin-4-yl)ethyl]piperazine dihydrochloride using
procedures substantially equivalent to those described for the
preparation of Intermediate C-26.
Intermediate C-28
1- [Boc-D,L- (2-Benzyloxycarbonylaminothiazol-4-yl)glycinyl] -4-
[2-(pyridin-4-yl)ethyl]piperazine.
Prepared from Boc-D,L-(2-benzyloxycarbonylaminothiazol-4-
yl)glycine and 1-[2-{pyridin-4-yl) ethyl]piperazine
dihydrochloride using procedures substantially equivalent to
those described for the preparation of Intermediate C-26.
Preparation of Intermediates D-l - D-28
The following compounds were prepared according to the
indicated method (Method D-A, Method D-B, Method D-C,
Method D-D or Method D-F) from the indicated starting
material, unless otherwise described.
Intermediate D-l
1-(D-Phenylglycinyl)-4-[2-(4-pyridinyl)ethyl]piperazine
Hydrochloride.
Method D-A
1-(Boc-D-phenylglycinyl)-4-[2-(4-pyridinyl)ethyl]-
piperazine (13 g, 30.6 mmol) and anisole (50 mL) were
dissolved in methanol and cooled to 0 °C. Concentrated
hydrochloric acid (40 mL, 300 mmol) was added dropwise to the
solution, and the mixture allowed to warm to room temperature.
The mixture stirred for 1 h, and the solvent and anisole were
removed under vacuum. The residue was suspended in diethyl
ether and sonicated for 1 h. The solid product was filtered
and dried under vacuum (0.5 torr, 66 Pa at 50-60 °C) to give
1-(D-phenylglycinyl)-4-[2-(4-pyridinyl)ethyl]piperazine
hydrochloride (11.8 g, 89%) as a white, hygroscopic solid.
1H NMR (CD3OD)
API-MS, m/e = 325 (M+l)
Intermediate D-2
1-(D-Phenylglycinyl)-4-[2-(2-pyridinyl)ethyl]piperazine.
Prepared from 1-(Boc-D-phe.nylglycinyl)-4-[2-(2-pyridin-
yl) ethyl]piperazine using Method D-A.
1H NMR (CD3OD)
API-MS, m/e = 325 (M+l)
Intermediate D-3
1-(D-Phenylglycinyl)-4-[2-(2-pyrazinyl)ethyl]piperazine.
Prepared from 1-(Boc-D-phenylglycinyl)-4- [2-(2-pyrazin-
yl)ethyl]piperazine using Method D-A.
1H NMR (CD3OD)
API-MS, m/e = 326 (M+l)
Intermediate D-4
1-(D-Phenylglycinyl)-4-[2-(3-pyridazinyl)ethyl]piperazine.
Prepared from 1-(Boc-D-phenylglycinyl)-4-[2-(3-pyrid-
azinyl) ethyl] piperazine using Method D-A.
1H-NMR (CD3OD)
IS-MS, m/e 326 (M+l)
Intermediate D-5
1- (D-Phenylglycinyl)-4-[2-(3-pyridinyl) ethyl] piperazine.
Prepared from l-(Boc-D-phenylglycinyl)-4-[2-(3-pyridin-
yl)ethyl]piperazine using Method D-A.
1H NMR (CD3OD)
API-MS, m/e = 325 (M+l)
Intermediate D-6
1- (D-Phenylglycinyl)-4-[2-(4-imidazolyl)ethyl]piperazine.
Prepared from 1-(Boc-D-phenylglycinyl)-4-[2-(4-imid-
azolyl)ethyl]piperazine using Method D-A,
1H-NMR
IS-MS, m/e 314.1 (M+l)
Intermediate D-7
1- (D-Phenylglycinyl)-4-[2-(4-pyrazolyl)ethyl]piperazine.
Prepared from 1-(Boc-D-phenylglycinyl)-4-[2-(4-pyrazol-
yl) ethyl] piperazine using Method D-A.
1H-NMR
IS-MS, m/e 314.3 (M+l)
Intermediate D-8
1-(D-Phenylglycinyl)-4-[2-(1-imidazolyl)ethyl]piperazine.
Prepared from 1-(Boc-D-phenylglycinyl)-4-[2-(1-imid-
azolyl) ethyl] piperazine using Method D-A.
1H 1H-NMR
IS-MS, m/e 314.1 (M+l)
Intermediate D-9 (PD7-H7C-045, -046)
1-(D-Phenylglycinyl)-4-[2-(1-pyrazolyl)ethyl]piperazine.
Prepared from 1-(Boc-D-phenylglycinyl)-4-[2-(1-pyrazol-
yl) ethyl] piperazine using Method D-A.
1H-NMR
IS-MS, m/e 314.1 (M+l)
Intermediate D-10
1-[D,L-(Pyridin-2-yl)glycinyl]-4-[2-(4-pyridinyl)ethyl]-
piperazine.
Method D-B
To a stirring solution of 1-[Boc-D,L-(pyridin-2-yl)-
glycinyl]-4-[2-(4-pyridinyl)ethyl]piperazine (2.31 g, 5.4
mmol) in dichloromethane (45 mL) was added TFA (5 mL). After
6 h, the solvents were removed in vacuo. The residue was
partitioned between ethyl acetate and satd aq. NaHCO3, and the
layers were separated. The aqueous phase was extracted with
50% ethyl acetate/dichloromethane, then 5%
methanol/dichloromethane. The combined organic extracts were
dried with MgSO4, filtered and concentrated to give 1.66 g
(94%) of the title compound.
1H-NMR
IS-MS, m/e 326.1 (M+l)
Intermediate D-ll
1- [D,L-(2-Methoxyphenyl)glycinyl]-4-[2-(1-pyrazolyl)ethyl]-
piperazine.
Prepared from l-[Boc-D,L-(2-methoxyphenyl)glycinyl]-4-[2-
(1-pyrazolyl)ethyl]piperazine using Method D-B.
1H-NMR
IS-MS, m/e 355.1 (M+l)
Intermediate D-12
1- (D-Phenylglycinyl)-4-[2-(thiazol-2-yl)ethyl]piperazine
Trihydrochloride.
Prepared from 1-(Boc-D-phenylglycinyl)-4-[2-(thiazol-2-
yl)ethyl]piperazine using methods substantially equivalent to
those described in Method D-A (80%) .
1h NMR (CD3OD).
CI-MS, m/e = 331 (C17H22N4OS+1).
Intermediate D-13
1-(D-Phenylglycinyl)-4-[2-(2-benzyloxycarbonylaminothiazol-4-
yl)ethyl]piperazine Trihydrochloride.
Method D-C
1-(Boc-D-Phenylglycinyl)-4-[2-(2-benzyloxycarbonylamino-
thiazol-4-yl)ethyl]piperazine (520 mg, 0.898 mmol) was
dissolved in ethyl acetate (10 mL) and anisole (1 mL). The
mixture was cooled to 0 °C, and a saturated solution of HCl in
ethyl acetate was added. The mixture was allowed to warm to
room temperature and stirred for 4 h. The solvent was removed
under vacuum to provide the title compound as a white solid
(530 mg, quantitative).
1H NMR (CD3OD).
APCI-MS, m/e = 480 (C25H29N5O3S+I) .
Intermediate D-14
1-(D-Phenylglycinyl)-4-[2-(3-fluoropyridin-4-yl)ethyl]-
piperazine Trihydrochloride.
Prepared from 1-(Boc-D-phenylglycinyl)-4-[2-(3-fluoro-
pyridin-4-yl)ethyl]piperazine using a method substantially
equivalent to Method D-A (98%).
1H NMR (CD3OD).
APCI-MS, m/e = 353 (C19H23FN4O+1).
Intermediate D-15
1-(D-Phenylglycinyl)-4-[2-(2-cyanopyridin-4-yl)ethyl]-
piperazine Trihydrochloride.
Method D-D
1-(Boc-D-phenylglycinyl)-4-[2-(2-cyanopyridin-4-yl)-
ethyl]piperazine (580 mg, 1.29 mmol) and anisole (5.0 g, 4.64
mmol) were dissolved in methanol (10 mL) and cooled to -15 °C.
To this solution, concentrated (6 N) hydrochloric acid (1.2
mL, 11.6 mmol) was added, and the mixture stirred at -10 °C
for 1 hour. The solvents were removed under vacuum and the
residue co-evaporated with methanol, methanol and toluene, and
methanol and ethyl acetate to provide 1-(D-phenylglycinyl)-4-
[2-(2-cyanopyridin-4-yl)ethyl]piperazine trihydrochloride (600
mg, 100%) as an off white solid.
lH NMR (CD3OD) .
CI-MS, m/e = 350 (M+l) .
Intermediate D-16
1- [D,L- (2-Chlorophenyl)glycinyl]-4-(l-methylpiperidin-4-yl) -
piperazine.
Prepared from 1- [Boc-D, L-(2-chlorophenyl)glycinyl]-4-(1-
methylpiperidin-4-yl)piperazine using Method D-E.
1H NMR
IS-MS, m/e (M+l)
Intermediate D-17
1-[D,L-(Quinolin-8-yl)glycinyl]-4-(l-methylpiperidin-4-yl)-
piperazine.
Method D-E
To a stirring solution of 1-[Boc-D,L-(quinolin-8-yl)-
glycinyl]-4-(l-methylpiperidin-4-yl)piperazine (0.53 g, 1.13
mmol) and anisole (0.62 mL, 5.67 mmol) in dichloromethane (22
mL) was added TFA (2.2 mL) . After 4 h, the solvents were
removed in vacuo, and the residue was dissolved in methanol
and loaded onto an SCX column (pretreated with 5% acetic acid
in methanol and washed with methanol). The column was washed
with methanol and then the product was eluted with 30% (2 N
ammonia/methanol) in dichloromethane. The product containing
fractions were combined and concentrated in vacuo to give
approximately 0.4 g (quantitative) of the title compound.
1H NMR
Intermediate D-18
1- [D,L-(2-Trifluoromethylphenyl)glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine.
Prepared from 1-[Boc-D,L-(2-trifluoromethylphenyl)-
glycinyl]-4-(l-methylpiperidin-4-yDpiperazine using Method D-
E.
1H NMR
IS-MS, m/e 385.1 (M+l)
Intermediate D-19
1- [D-Cyclopentylglycinyl] -4- (l-methylpiperidin-4-yl) -
piperazine.
Prepared from 1-[Boc-D-cyclopentylglycinyl]-4-
(l-methylpiperidin-4-yl)piperazine using Method D-E.
1H NMR
IS-MS, m/e 309.2 (M+l)
Intermediate D-20
1-[D-Cyclohexylglycinyl]-4-(l-methylpiperidin-4-yl)piperazine.
Prepared from l-[Boc-D-cyclohexylglycinyl]-4-
(l-methylpiperidin-4-yl)piperazine using Method D-E.
1H NMR
IS-MS, m/e 323.3 (M+l)
Intermediate D-21
1- [D-Phenylglycinyl]-4-(2-phenethyl)piperazine .
Method D-F
1-(Cbz-D-Phenylglycinyl)-4-(2-phenethyl)piperazine (1.66
g; 3.63 mmol) was dissolved in methanol (46 mL) with 10% Pd/C
(3 94 tng) and reaction mixture was subjected to a balloon of
hydrogen for 15 h. Only 5 0% conversion was observed; so the
catalyst was filtered through diatomaceous earth, and the
mixture was re-subjected to the same conditions for 17 h. The
catalyst was filtered through diatomaceous earth, and the
solvent was removed under vacuum to give the title compound
(1.03 g; 88%).
1H NMR (CDC13) .
APCI-MS, m/e m 324 (M+l).
Intermediate D-22
1-[D,L-(Thiazol-2-yl)glycinyl]-4-(l-methylpiperidin-4-yl)-
piperazine Trihydrochloride.
Prepared from l-[Boc-D,L-(thiazol-2-yl)glycinyl]-4-
(l-methylpiperidin-4-yl)piperazine using Method A-A. In this
procedure, saturated HCl in 1,4-dioxane was used in place of
saturated HCl in methanol. Concentration of the reaction
mixture provided the title compound as a crude residue that
was used directly without purification.
Intermediate D-23
1-[D,L-(Benzo[b]thiophen-3-yl)glycinyl]-4-(1-methylpiperidin-
4-yl)piperazine Trihydrochloride.
Prepared from 1-[Boc-D,L-(benzo[b]thiophen-2-yl)-
glycinyl]-4-(l-methylpiperidin-4-yl)piperazine using Method A-
A. Part B. In this nrocedure. saturated HCl in 1,4-dioxane
was used in place of saturated HCl in methanol.
LCMS m/z 373.5 (M+l)
Intermediate D-24
1-[D,L-(Naphthalen-l-yl)glycinyl]-4-(l-methylpiperidin-4-yl)-
piperazine Trihydrochloride.
Prepared from 1- [Boc-D,L-(naphthalen-l-yl)glycinyl]-4-(1-
methylpiperidin-4-yl)piperazine using Method A-A, Part B. In
this procedure, saturated HCl in 1,4-dioxane was used in place
of saturated HCl in methanol.
1H NMR
IS-MS m/e 367.0 (M+l)
Intermediate D-25
1-D,L-(2-Methylsul£onylphenyl)glycinyl-4-(l-methylpiperidin-4-
yl)piperazine.
Prepared from 1-[Boc-D,L-(2-methylsulfonylphenyl)-
glycinyl]-4-(l-tnethylpiperidin-4-yl)piperazine using Method D-
D.
1H-NMR
IS-MS, m/e 395 (M+l)
Intermediate D-26
1-[D,L-(Thiazol-5-yl)glycinyl]-4-[2-(pyridin-4-yl)ethyl]-
piperazine.
To a stirred solution of crude 1-[D,L-(thiazol-5-yl)-
glycinyl]-4-[2-(pyridin-4-yl)ethyl]piperazine (circa 5.15
mmol) and anisole (11.2 mL) in dichloromethane (4 2 mL) at room
temperature was added TFA (10.5 mL), and the mixture stirred
at room temperature for 16 h before concentrating in vacuo.
The product was isolated using SCX ion exchange
chromatography.
NMR
Intermediate D-27
1- [D;L-(2-Methylthiazol-4-yDglycinyl]-4- [2- (pyridin-4-yl) -
ethyl]piperazine.
Prepared from 1-[Boc-D,L-(2-methylthiazol-4-yDglycinyl]-
4-[2-(pyridin-4-yl)ethyl]piperazine using procedures
substantially equivalent to those described in the preparation
of Intermediate D-26.
NMR
Intermediate D-28
1- [D,L-(2-Aminothiazol-4-yDglycinyl]-4-[2-(pyridin-4-yl)-
ethyl]piperazine.
A stirred solution of 1-(Boc-D,L-2-benzyloxycarbonyl-
aminothiazol-4-ylglycinyl)-4-[2-(pyridin-4-yl)ethyl] piperazine
(crude, circa 4.2 mmol) in a mixture of HBr-acetic acid (50%,
35 mL) and acetic acid (70 mL) was heated at 60 °C for 6 h,
cooled and then concentrated in vacuo. The title product was
isolated using SCX ion exchange chromatography.
NMR
Preparation of Intermediates E
The following compounds were prepared according to the
indicated method (Method E-A) from the indicated starting
material, unless otherwise described.
Intermediate E-l
l-Boc-4-(Cbz-D-phenylglycinyl)piperazine.
Method E-A
D-Cbz-phenylglycine (58.0 g, 203 mmol) and 1-Boc-
piperazine (41.7 g, 224 mmol) were dissolved in DMF (1 L) and
cooled to approximately -15 °C in an ice-methanol bath.
Diethyl cyanophosphonate (37.0 mL, 244 mmol) was slowly added
to the mixture. Triethylamine (59.4 mL, 426 mmol) was added
dropwise to the solution. The mixture was stirred at -15 °C
for 2 h and was allowed to gradually warm to room temperature
overnight. The mixture was diluted with ethyl acetate and
water. The layers were separated, and the water layer
extracted with ethyl acetate. The organic layers were
combined, washed with 10% citric acid (2 x 500 mL) and brine,
dried (Na2SO4), filtered and concentrated under vacuum. The
crude product was filtered through a plug of silica gel (1.2
kg) using 1:1 hexanes:ethyl acetate as eluent to provide 1-
Boc-4-(Cbz-D-phenylglycinyl)piperazine (69.9 g, 76%) as a
colorless oil.
1H-NMR(CDC13)
API-MS, m/e = 454 (M+l)
Preparation of Intermediates F
The following compounds were prepared according to the
indicated method (Method F-A) from the indicated starting
material, unless otherwise described.
Intermediate F-l
l-Boc-4-(D-phenylglycinyl)piperazine.
Method F-A
l-Boc-4-(Cbz-D-phenylglycinyl)piperazine (69.5 g, 153
mmol) was dissarved in ethanol (500 mL). The mixture was
degassed with nitrogen and 10% Pd/C (6.8 g) was added.
Hydrogen was bubbled through the mixture for 1 h, and it was
maintained under a hydrogen atmosphere for 16 h. The Pd/C was
removed by filtration through cellulose. The filter cake was
rinsed with ethanol and ethyl acetate. The filtrate was
concentrated under vacuum to give l-Boc-4-
(D-phenylglycinyl)piperazine (45.3 g, 93%) as a light yellow
solid.
1H-NMR(CDC13)
API-MS, m/e = 320 (M+l)
Preparation of Intermediates G
The following compounds were prepared according to the
indicated method (Method G-A) from the indicated starting
material, unless otherwise described.
Intermediate G-l
l-Boc-4-(4-Methoxybenzoyl-D-phenylglycinyl)piperazine.
Method G-A
l-Boc-4-(D-phenylglycinyl)piperazine (42.0 g, 131.5 mmol)
was dissolved in 1,4-dioxane (420 mL) and water (210 mL) and
was cooled to 10 °C. Potassium carbonate (36.4 g, 263 mmol)
was added, followed by p-methoxybenzoyl chloride (24.7 g, 144
mmol). The mixture stirred at room temperature overnight.
The mixture was diluted with water and ethyl acetate. The
layers were separated and the water layer extracted with ethyl
acetate. The organic layers were combined, washed with brine,
dried, filtered and concentrated to provide l-Boc-4-(4-
methoxybenzoyl-D-phenylglycinyl)piperazine (58.7 g, 98%) as an
off-white solid.
1H-NMR(CDC13)
API-MS, m/e = 454 (M+l)
Preparation of Intermediates H
The following compounds were prepared according to the
indicated method (Method H-A) from the indicated starting
material, unless otherwise described.
Intermediate H-l
1-(4-Methoxybenzoyl-D-phenylglycinyl)piperazine
Trifluoroacetate.
Method H-A
l-Boc-4-(4-Methoxybenzoyl-D-phenylglycinyl)piperazine
(20.0 g, 44.1 mmol) was dissolved in dichloromethane (50 mL)
and anisole (20 mL). To this vigorously stirred mixture was
added trifluoroacetic acid (50 mL). The mixture was stirred
for 25 min at room temperature. The solvents were removed
under vacuum. The residue was triturated in ether and
sonicated for 60 min. The solid was collected by filtration
and dried in a vacuum pistol overnight to provide
1- (4-methoxybenzoyl-D-phenylglycinyl)piperazine
trifluoroacetate (18.2 g, 88%) as a light yellow solid.
1H-NMR(CD3OD)
API-MS, m/e = 354 (M+l)
Preparation of Examples
The following examples of formula (I) were prepared
according to the indicated method (Method I-A, Method I-B,
Method I-C, Method I-D, Method I-E, Method I-F or Method I-G)
from the indicated starting materials, unless otherwise
described.
Example 1
1- (4-Methoxybenzoyl-D-phenyiglycinyl)-4-phenethylpiperazine.
Method I-A
To a stirring solution of 1-(4-methoxybenzoyl-D-phenyl-
glycinyDpiperazine (0.05 g, 0.14 mmol) in methanol (1 mL) was
added phenylacetaldehyde (0.17 mL, 1.4 mmol), followed by
acetic acid (0.05 mL, 0.87 mmol) and then sodium
cyanoborohydride (0.014 g, 0.21 mmol). After 2 h, the
solution was loaded onto an SCX column, which was pretreated
with 5% acetic acid/methanol. The column was washed with
methanol and then the product was eluted with 10/1
dichloromethane:(2 N NH3 in methanol). The product containing
fractions were combined and concentrated to give 63 mg of
thick oil (90% pure by analytical HPLC). The crude product
was dissolved in a minimal volume of dichloromethane and
chromatographed over silica gel, eluting with dichloromethane,
followed by ethyl acetate, followed by a gradient of 2%
through 10% (2 N NH3/methanol) in dichloromethane. The
product containing fractions were combined and concentrated to
give 0.022 g (34%) of the title compound.
1H-NMR
IS-MS, m/e 458.0 (M+l)
HPLC Analysis (Method A): 100% tr = 27.44 min.
Example 2
1- (4-Methoxybenzoyl-D-phenylglycinyl) -4- [2- (4-pyridinyl) -
ethyl]piperazine Diydrochloride.
Method I-B
1- (D-Phenylglycinyl)-4-[2-(4-pyridinyl) ethyl] piperazine
trihydrochloride (1.0 g, 2.31 mmol) and potassium carbonate
(2.0 g, 144.4 mmol) were dissolved in 1,4-dioxane (5 mL) and
water (1 mL) . To this solution, p-anisoyl chloride (650 µL,
4.62 mmol) was added. The mixture stirred at room temperature
for 3 h. The mixture was diluted with water, and the mixture
extracted with ethyl acetate. The organic layers were
combined, washed with brine, dried (Na2SO4) , filtered and
concentrated. The residue was dissolved in methanol and
loaded onto an SCX column (10 g, pretreated with 5% acetic
acid in methanol and washed with methanol) . The by-products
were eluted with methanol (about 20 mL) , and desired product
eluted with saturated ammonia in methanol. The product was
further purified by column chromatography (SiO2, CH2C12:CMA
20:1 to 9:1 gradient). The product was dissolved in methanol,
and HC1 in diethyl ether was added to provide l-(4-
methoxybenzoyl-D-phenylglycinyl)-4-[2-(4-
pyridinyl)ethyl]piperazine hydrochloride (370 mg, 37%) as an
off white solid.
1H-NMR(CDC13)
CI-MS, m/e = 459 (M+l)
Analysis for C27H30N4O3-2.2 HC1-1.1 H2O.0.4 NH4C1:
Calcd: C, 55.91/ H, 6.26; N, 10.63;
Found: C, 56.04; H, 6.55; N, 10.46.
HPLC Analysis (Method B): 99.7%, tR = 10.98 min.
Example 3
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(4-pyridinyl)-
ethyl]piperazine.
Method I-C
1-(D-Phenylglycinyl)-4-[2-(4-pyridinyl)ethyl]piperazine
(1.0 g, 2.31 mmol), 6-carboxyindole (371 mg, 2.31 mmol), HOBt
(312 mg, 2.31 mmol), Et3N (1.3 mL, 9.24 mmol), and DCC (620
mg, 3.00 mmol) were stirred in DMF at room temperature
overnight. The precipitate was removed by filtration, and the
filtrate concentrated under vacuum to a thick paste. The
residue was dissolved in methanol and purified by ion exchange
chromatography (SCX resin, methanol then saturated NH3 in
methanol) to provide the crude product as a brown solid. The
crude product was purified by chromatography (SiO2, 20:1
CH2Cl2:CMA to 6:1 CH2Cl2:CMA) to provide 1-(indole-6-carbonyl-
D-phenylglycinyl)-4-[2-(4-pyridinyl)ethyl]piperazine (350 mg,
32%) as an off white solid.
Melting Point = 75-80 °C
IR (thin film)
1H NMR (CDCI3)
Analysis for C28H29N4O3:
Calcd: C, 50.12; H, 5.06; N, 7.54;
Found: C, 49.81; H, 5.33; N, 7.39.
HPLC Analysis (Method B): >99% tr = 12.4 min.
Example 3a
1- (lndole-6-carbonyl-D-phenylglycinyl)-4-[2-(4-pyridinyl)-
ethyl]piperazine Dihydrochloride.
Prepared from 1-(indole-6-carbonyl-D-phenylglycinyl)-
4-[2-(4-pyridinyl)ethyl]piperazine using Method I-D (but using
dichloromethane as the initial solvent).
1H NMR
IS-MS, m/e 468.2 (M+l)
Analysis for C28H29N5O2 1.9 HCl 2.0 H2O:
Calcd: C, 58.70; H, 6.14; N, 12.22; Cl, 11.76;
Found: C, 58.86; H, 5.62; N, 12.07; Cl, 11.78.
HPLC Analysis (Method A): 100 % tr = 19.24 min.
Example 4
1- (3-Chloroindole-6-carbonyl-D-phenylglycinyl) -
4-[2-(4-pyridinyl)ethyl]piperazine.
Prepared from 3-chloroindole-6-carboxylic acid and 1-(D-
phenylglycinyl)-4-[2-(4-pyridinyl)ethyl]piperazine using
Method I-C.
Melting point = 100-105 °C
1H-NMR (CDCI3)
API-MS, m/e = 502 (M+l)
Analysis for C28H28ClN5O2 1.2 H2O:
Calcd: C, 64.23; H, 5.85; N, 13.37;
Found: C, 64.38; H, 5.74; N, 13.22.
HPLC Analysis (Method B): 97.2% tr = 13.8 min.
Example 4a
1-(3-Chloroindole-6-carbonyl-D-phenylglycinyl)-4-
[2- (4-pyridinyl) ethyl] piperazine Dihydrochloride ..
Prepared from 1-(3-chloroindole-6-carbonyl-D-
phenylglycinyl)-4-[2-(4-pyridinyl)ethyl]piperazine using
Method I-D (but using dichloromethane as the initial solvent).
1H NMR
IS-MS, m/e 502.1 (M+l)
Analysis for C28H28C1N5O2 2.0 HCl 1.8 H2O:
Calcd: C, 55.37; H, 5.58; N, 11.53; Cl, 17.51;
Found: C, 55.03; H, 5.34; N, 11.30; Cl, 17.26.
HPLC Analysis (Method A) : 100 % tr = 24.55 min.
Example 5
1-(5-Chloroindole-2-carbonyl-D-phenylglycinyl)-
4-[2-(4-pyridinyl)ethyl]piperazine.
Prepared from 5-chloroindole-2-carboxylic acid and 1-(D-
phenylglycinyl) -4- [2- (4-pyridinyl) ethyl] piperazine using
Method I-C.
Melting Point = 106-110 °C
IR (thin film)
1H-NMR (CDCl3)
API-MS, m/e = 502 (M+l)
HPLC Analysis (Method B): 88.7% tr = 14.9 min.
Example 6
1-(Indole-2-carbonyl-D-phenylglycinyl)-4-[2-(4-pyridinyl)-
ethyl]piperazine.
Prepared from indole-2-carboxylic acid and 1-(D-phenyl-
glycinyl)-4-[2-(4-pyridinyl)ethyl]piperazine using Method I-C.
Melting point = 95-100 °C
1H-NMR (CDCI3)
IR (thin film)
API-MS, m/e 468 (M+l)
Analysis for C28H29N5O2 1.7 H2O:
Calcd: C, 67.51; H, 6.55; N, 14.06;
Found: C, 67.00; H, 6.10; N, 14.02.
HPLC Analysis (Method B): 96.5% tr = 13.5 min.
Example 7
1-(3-Methylindole-6-carbonyl-D-phenylglycinyl)-
4-[2-(4-pyridinyl)ethyl]piperazine.
Prepared from 3-methylindole-6-carboxylic acid and 1- (D-
phenylglycinyl)-4- [2-(4-pyridinyl)ethyl]piperazine using
Method I-C.
Melting point = 62-65 °C
1H-NMR (CDC13)
IR (thin film)
API-MS, m/e 482 (M+l)
Analysis for C29H31N5O2 1.6 H2O:
Calcd: C, 68.24; H, 6.75; N, 13.72;
Found: C, 68.25; H, 6.66; N, 13.78.
HPLC Analysis (Method B): 93.6% tr = 13.3 min.
Example 8
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-[2-(2-pyridinyl)-
ethyl]piperazine.
Prepared from 4-methoxybenzoyl chloride and
1-(D-phenylglycinyl)-4-[2-(2-pyridinyl)ethyl]piperazine using
Method I-B.
Melting point = 168-180 °C
[a]25D -87.7 (c 1.00, methanol)
1H-NMR (CD3OD)
CI-MS, m/e = 459 (M+l)
Analysis for C27H30N4O2.2.OHC1•0.9H2O:
Calcd: C, 59.21; H, 6.22; N, 10.23; Cl, 12.95,
Found: C, 58.88; H, 6.25; N, 10.19; Cl, 13.26.
HPLC Analysis (Method B); 97.5% tr = 12.2 min.
Example 9
1-(3-Chloroindole-6-carbonyl-D-phenylglycinyl)-
4-[2-(2-pyridinyl)ethyl]piperazine.
Prepared from 3-chloroindole-6-carboxylic acid and 1-(D-
phenylglycinyl)-4- [2-(2-pyridinyl)ethyl] piperazine using
Method I-C.
Melting point = 93-96 °C
[a]25d -72.4 (c 0.61, chloroform)
1H-NMR (CDCl3)
CI-MS, m/e = 502 (M+l)
Analysis for C28H28N5O2 0.4 H2O:
Calcd: C, 66.04; H, 5.07; N, 13.75; Cl, 6.96;
Found: C, 65.94; H, 5.61; N, 13.74; Cl, 6.91.
HPLC Analysis (Method B): 98.3% tr = 14.1 min.
Example 10
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(2-pyridinyl)-
ethyl]piperazine.
Prepared from indole-6-carboxylic acid and
1-(D-phenylglycinyl)-4-[2-(2-pyridinyl)ethyl]piperazine using
Method I-C.
Melting point = 73-78 °C
[a]25D -90.9 (c 0.25, chloroform)
1H-NMR (CDCl3)
CI-MS, m/e = 468 (M+l)
Analysis for C28H28N5O2 0.6 H2O;
Calcd: C, 70.30; H, 6.36; N, 14.64;
Found: C, 70.39; H, 6.30; N, 14.62.
HPLC Analysis (Method B): 98.3% tr = 14.1 min.
Example 11
1-[4-Methoxybenzoyl-D,L-(pyridin-2-yl)glycinyl]-
4-[2-(4-pyridinyl)ethyl]piperazine Trihydrochloride.
Prepared from 4-methoxybenzoic acid and 1-[D,L-(pyridin-
2-yl) glycinyl] -4- [2- (4-pyridinyl) ethyl] piperazine using Method
I-C.
1H-NMR
IS-MS, m/e 460.3 (M+l)
Analysis for C26H29N5O3 3.5 HC1 4 H20:
Calcd: C, 47.37; H, 6.19; N, 10.62;
Found: C, 47.17; H, 5.75; N, 10.56.
HPLC Analysis (Method A): 100% tr = 10.48 min.
Example 12
1- [3-Chloroindole-6-carbonyl-D,L- (pyridin-2-yl)glycinyl] -4- [2-
(4-pyridinyl) ethyl] piperazine Trihydrochloride.
Prepared from 3-chloroindole-6-carboxylic acid and
1- [D,L- (pyridin-2-yl)glycinyl] -4- [2- (4-pyridinyl) ethyl] -
piperazine using Method I-C.
1H-NMR
IS-MS, m/e 503.5 (M+l)
Analysis for C27H27N6O2Cl•3 HCl•5 H2O:
Calcd: C, 46.16; H, 5.74; N, 11.96; Cl, 20.19;
Found: C, 46.10; H, 5.59; N, 11.68; Cl, 20.29.
HPLC Analysis (Method A): 99% tr = 18.64 min.
Example 13
1-[3-Methylindole-6-carbonyl-D,L-(pyridin-2-yl)glycinyl] -4- [2-
(4-pyridinyl)ethyl]piperazine.
Prepared from 3-methylindole-6-carboxylic acid and
1- [D,L- (pyridin-2-yl)glycinyl] -4- [2- (4-pyridinyl) ethyl] -
piperazine using Method I-C.
1H-NMR
IS-MS, m/e 483.5 (M+l)
HPLC Analysis (Method A): 99% tr = 16.14 min.
Example 14
1- [Indole-6-carbonyl-D,L- (pyridin-2-yl) glycinyl] -
4-[2-(4-pyridinyl)ethyl]piperazine.
Prepared from indole-6-carboxylic acid and 1-[D,L-
(pyridin-2-yl) glycinyl] -4- [2- (4-pyridinyl) ethyl] piperazine
using Method I-C.
1H-NMR
IS-MS, m/e 469.3 (M+l)
HPLC Analysis (Method A): 100% tr = 12.87 min.
Example 15
1- (Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(3-pyridinyl)-
ethyl] piperazine.
Prepared from indole-6-carboxylic acid and l-(D-phenyl-
glycinyl)-4-[2-(3-pyridinyl) ethyl]piperazine using Method I-C.
Melting point = 82-87 °C
[a]25D -116.0 (c 0.25, methanol)
IR (thin film)
1H-NMR (CDC13)
API-MS, m/e = 468 (M+l)
Analysis for C28H29N5O2•1.25 H2O:
Calcd: C, 68.62; H, 6.48; N, 14.29;
Pound: C, 68.49; H, 6.39; N, 14.13.
HPLC Analysis (Method B) : >99% tr = 12.3 min.
Example 16
1- (lhdole-6-carbonyl-D-phenylglycinyl)-4-[2-(2-pyrazinyl)-
ethyl]piperazine.
Prepared from indole-6-carboxylic acid and 1-(D-phenyl-
glycinyl)-4-[2-(2-pyrazinyl) ethyl]piperazine using Method I-C.
Melting Point = 53-58 °C
[a]25D -91.4 (c 0.23, chloroform)
1H-NMR (CDCl3)
IR (thin film)
API-MS, m/e 469 (M+l)
Analysis for C27H28N6O2•1.6 H2O:
Calcd: C, 65.20; H, 6.32; N, 16.90;
Found: C, 65.49; H, 6.02; N, 16.54.
HPLC Analysis (Method B) : 98.5% tr = 13.6 min.
Example 17
1- (Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(1-imidazolyl)-
ethyl]piperazine.
Prepared from indole-6-carboxylic acid and 1-(D-phenyl-
glycinyl)-4- [2-(1-imidazolyl)ethyl]piperazine using Method I-
C.
1H-NMR
IS-MS, m/e 457.3 (M+l)
Analysis for C26H28N6O2•1.1 H2O;
Calcd: C, 65.55; H, 6.39; N, 17.64;
Found: C, 66.01; H, 6.23; N, 17.14.
HPLC Analysis (Method A) : 99% tr = 19.66 min.
Example 18
1- (Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(1-pyrazolyl)-
ethyl]piperazine.
Prepared from indole-6-carboxylic acid and 1- (D-phenyl-
glycinyl)-4-[2-(1-pyrazolyl)ethyl]piperazine using Method I-C.
1H-NMR
IS-MS, m/e 457.2 (M+l)
Analysis for C26H28N6O2•1.3 H2O:
Calcd: C, 65.06; H, 6.43; N, 17.51;
Found: C, 65.39; H, 6.53; N, 16.98.
HPLC Analysis (Method A):>97% tr = 22.98 min.
Example 19
1- (Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(4-imidazolyl) -
ethyl]piperazine Dihydrochloride.
Prepared from indole-6-carboxylic acid and 1- (D-phenyl-
glycinyl)-4-[2-(4-imidazolyl)ethyl]piperazine using Method I-
C.
1H-NMR
IS-MS, m/e 457.3 (M+l)
Analysis for C26H28N6O2•2.1 HCl•4.0 H2O:
Calcd: C, 51.60; H, 6.35;N, 13.89; Cl, 12.30;
Found: C, 51.82; H, 6.04; N, 13.56; Cl, 12.12.
HPLC Analysis (Method A): 94% tr = 17.78 min.
Example 2 0
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(4-pyrazolyl)-
ethyl]piperazine Hydrochloride.
Prepared from indole-6-carboxylic acid and 1-(D-phenyl-
glycinyl)-4-[2-(4-pyrazolyl)ethyl]piperazine using Method I-C.
1H-NMR
IS-MS, m/e 457.3 (M+l)
Analysis for C26H28N6O2•1.3 HCl•1.75 H2O:
Calcd: C, 58.32; H, 6.17; N, 15.70; Cl, 8.61;
Found: C, 58.31; H, 5.72; N; 15.48; Cl, 8.37.
HPLC Analysis (Method A): >98% tr = 19.95 min.
Example 21
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-[2-(3-pyridazinyl)-
ethyl]piperazine.
Prepared from indole-6-carboxylic acid and 1-(D-phenyl-
glycinyl) -4- [2- (3-pyridazinyl) ethyl] piperazine using Method I-
C.
Melting Point = 219-222 °C with decomposition
1H NMR (CDC13)
[a]25D -53.9° (c 0.25, dimethyl sulfoxide)
API-MS, m/e = 469 (M+l)
HPLC Analysis (Method B): >99% tr = 12.8 min.
Example 22
1-[4-Methoxybenzoyl-D,L-(2-methoxyphenyl)glycinyl]-
4-[2-(4-pyridinyl)ethyl]piperazine.
Prepared from 4-methoxybenzoic acid and 1-[D,L-(2-meth-
oxyphenyl) glycinyl] -4- [2- (4-pyridinyl)ethyl]piperazine using
Method I-C.
1H-NMR
IS-MS, m/e 489.1 (M+l)
Analysis for C28H32N4O4•0.5 H2O:
Calcd: C, 67.59; H, 6.68; N, 11.26;
Found: C, 67.57; H, 6.49; N, 11.11.
HPLC Analysis (Method A): 97.2% tr.= 16.02 min.
Example 23
1- [Indole-6-carbonyl-D,L- (2-methoxyphenyl)glycinyl] -
4-[2-(4-pyridinyl)ethyl]piperazine Dihydrochloride.
Prepared from indole-6-carboxylic acid and l-[D,L-(2-
methoxyphenyDglycinyl] -4- [2- (4-pyridinyl) ethyl] piperazine
using Method I-C, followed by Method I-D.
1H-NMR
IS-MS, m/e 498.0 (M+l)
Analysis for C29H31N5O3 2.1 HC1•2.5 H2O:
Calcd: C, 56.25; H, 6.20; N, 11.31; Cl, 12.02;
Found: C, 56.56; H, 5.83; N, 11.21; Cl, 12.13.
HPLC Analysis (Method A): 100% tr = 17.24 min.
Methods for Examples 24 - 25
The compounds of Examples 24 and 25 were prepared by
coupling Boc-D-4-carboxamidophenylglycine to the appropriate
amine with EDCI/HOAt (similar to Method C-C), deprotection
with TFA/DCM (similar to Method D-B) and coupling to 3-amino-
4-chlorobenzoic acid with EDCI/HOAt (similar to Method I-C).
Example 24
1- [3-Amino-4-chlorobenzoyl-D- (4-carboxamidophenyl) glycinyl] -
4-(2-phenylethyl)piperazine.
HPLC (Method C) rt ll.lmin.
LCMS M+l 521.
NMR
Example 25
1-[3-Amino-4-chlorobenzoyl-D-4-carboxamidophenylglycinyl)-4-
benzylpiperazine.
HPLC (Method C) rt 11.4min.
LCMS M+l 512 .
NMR
Example 26
1-[Indole-6-carbonyl-D-(4-carboxyphenyl)glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine.
By coupling of Boc-D-4-carboxymethylphenylglycine with
1-(l-methylpiperidin-4-yl)piperazine using HOAt and EDCI
(similar to Method C-C), followed by TFA deprotection (similar
to Method D-B), coupling to indole-6-carboxylic acid using
HOAt and EDCI (similar to Method I-C) followed by hydrolysis
of the methyl ester with lithium hydroxide.
HPLC (Method C) rt, 6.05min
LCMS M+l 504
Nmr.
Example 27
1- (4-Methoxybenzoyl-D-phenylglycinyl)-4-(4-piperidinylmethyl)-
piperazine Trifluoroacetate.
Preparation of Starting Materials
1-Boc-isonipecotic acid.
Isonipecotic acid (15.0 g, 116 mmol) was dissolved in THF (300
mL), water (150 mL) and 6 N NaOH (4 0 mL). Di-tert-butyl
dicarbonate (26.6 g, 122 mmol) was added and the mixture
stirred overnight. The mixture was diluted with water and
ethyl acetate, and the layers separated. The water layers
were extracted with ethyl acetate, and the organic layers
discarded. The water layer was diluted with KHSO4 (2 N, pH~4)
and extracted with ethyl acetate. The organic layer was
washed with brine, dried (Na2SO4) , filtered and concentrated
to provide 1-Boc-isonipecotic acid (23.9 g, 90%) as a white
solid.
1H-NMR(CDC13)
API-MS, m/e = 230 (M+l)
l-Boc-piperidine-4-methanol.
1-Boc-isonipecotic acid (10.0 g, 214 mtnol) was dissolved in
THF (400 mL) and cooled to 0 °C. A solution of BH3 THF
(180 mL, 1 N in THF, 180 mmol) was added slowly. The mixture
stirred for 1 h at 0 °C and was allowed to warm to room
temperature for 12 h. The mixture was carefully quenched with
water and diluted with ethyl acetate. The water layer was
extracted with ethyl acetate. The organic layers were
combined, washed with brine, dried (Na2SO4), filtered and
concentrated to provide l-Boc-piperidine-4-methanol (7.98 g,
85%) as a white solid.
1H-NMR(CDC13)
API-MS, m/e = 220 (M+l)
l-Boc-piperidine-4-carboxaldehyde.
Dimethyl sulfoxide (3.5 mL, 4 8.7 mmol) was dissolved in
dichloromethane (100 mL) and was cooled to -78 °C. Oxalyl
chloride (3.65 mL, 41.8 mmol) was added. The mixture stirred
for 3 0 min. To this solution was added a solution of 1-Boc-
piperidine-4-methanol (7.5 g, 34.8 mmol) in dichloromethane
(15 mL) , and the mixture stirred for 1 h. Triethylamine (9.7
mL, 69.6 mmol) was added slowly and the mixture stirred at -78
°C for 30 min and warmed to room temperature over the course
of 1 h. The mixture was diluted with water and the layers
separated. The water layer was extracted with dichloromethane
and the organic layers combined, dried (Na2SO4), filtered and
concentrated to provide l-Boc-piperidine~4-carboxaldehyde
(6.75 g, 91%) as a yellow oil.
1H-NMR(CDC13)
API-MS, m/e = 214 (M+l)
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(l-Boc-piperidin-4-
ylmethyl)piperazine.
Prepared from 1-(4-methoxybenzoyl-D-phenylglycinyl)-
piperazine trifluoroacetate and l-Boc-piperidine-4-
carboxaldehyde using Method I-A (but using sodium
triacetoxyborohydride in 1,2-dichloroethane)(85%).
1H-NMR(CDC13)
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(4-piperidinyl-
methyl)piperazine trifluoroacetat;e.
Prepared from 1-(4-methoxybenzoyl-D-phenylglycinyl)-4-(1-
Boc-piperidin-4-ylmethyl)piperazine using Method H-A (90%).
Melting Point = 70-72 °C with decomposition
IR(KBr)
1H-NMR(CD3OD)
API-MS, m/e = 451 (M+l)
Analysis for C26H34N4O3•2.5 TFA•0.4 H2O:
Calcd: C, 50.12; H, 5.06; N, 7.54;
Found: C, 49.81; H, 5.33; N, 7.39.
HPLC Analysis (Method B): 97.1% RT=14.3 min.
Methods for Examples 2 8 - 29
Unless otherwise indicated, using Method I-A, the title compounds
were prepared from 1-(4-methoxybenzoyl-D-phenylglycinyl)-4-(4-
piperidinylmethyl)piperazine trifluoroacecate and the indicated
aldehyde or ketone.
Example 28
1- (4-Methoxybenzoyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
ylmethyl)piperazine.
Prepared from paraformaldehyde (56%) .
IR (KBr)
1H-NMR(CD3OD)
CI-MS, m/e = 465 (M+l)
Example 2 9
1- (4-Methoxybenzoyl-D-phenylglycinyl)-4-(1-isopropyl-
piperidin-4-ylmethyl)piperazine Trihydrochloride.
Prepared from acetone using Method I-A, followed by Method
I-D (but using methanol in place of ether/dichloromethane) (72%).
Melting Point = 172-180 °C with decomposition
IR (KBr)
1H-NMR(CD3OD)
CI-MS, m/e = 493 (M+l)
Analysis for C29H40N4O3•3 HC1:
Calcd: C, 55.85; H, 7.34; N, 8.98;
Found: C, 55.63; H, 7.32; N, 8.66.
HPLC Analysis (Method B): 98.2% RT=14.4 min.
Example 3 0
1- (4-Methoxybenzoyl-D-phenylglycinyl)-4-(2-eye1opentylethyl)-
piperazine
Preparation of Starting Materials:
Cyclopentylacetaldehyde.
Prepared from 2-cyclopentylethanol using the Dess-Martin
oxidation (Dess, D. B.; Martin, J. C; J. Am. Chem. Soc,
1991, 113, 7277). The aldehyde was used with trace amounts of
ether and methylene chloride present due to volatility of
product.
1H NMR (CDC13)
1- (4-Methoxybenzoyl-D-phenylglycinyl) -4- (2-cyclopentylethyl) -
piperazine.
Prepared from cyclopentylacetaldehyde using Method I-A
(58%) .
1H NMR (CDC13)
Example 3 0A
1- (4-Methoxybenzoyl-D-phenylglycinyl)-4-(2-cyclopentylethyl)-
piperazine Hydrochloride Hydrate.
Method I-D
To a stirred solution of 1-(4-methoxybenzyl-D-phenyl-
glycinyl)-4-2-cyclopentylethyl)piperazine (260 rng, 0.58 mmol)
in ether (10 mL) and methylene chloride (1 mL) was added
hydrogen chloride as a 2 N solution in ether (about 2 mL) , and
the resulting precipitate was filtered to give 1-(4-
methoxybenzoyl-D-phenylglycinyl) -4- (2-cyclopentyl-
ethyl) piperazine hydrochloride as a pale yellow solid.
1H NMR (CD3OD)
IS-MS, m/e = 450 (M+l)
Analysis for C27H35N3O3-HC1-0.5 H2O:
Calcd: C, 65.51; H, 7.53; N, 8.49;
Found: C, 65.67; H, 7.58; N, 8.13.
HPLC Analysis (Method D): >99%, RT=15.84
Melting Point = 190-192 °C
Example 31
1- (4-Methoxybenzoyl-D-phenylglycinyl) -4- (3-pyrrolidinyl) -
piperazine Trifluoroacetate.
Preparation of Starting Materials
(R)-(+)-l-Boc-3-pyrrolidinol.
To a stirred solution of (R) - ( + ) -3-pyrrolidinol (2 g,
22.96 mmol) in tetrahydrofuran (60 mL) and water (30 mL) was
added di-tert-butyl dicarbonate (5.27 g, 24.15 mmol) and 3 N
sodium hydroxide (16 mL), and the resulting solution was
stirred for 6 h. Another portion of di-tert-butyl dicarbonate
(0.74 g, 0.34 mmol) was added and the solution was stirred
overnight. The reaction was diluted with water (40 mL) and
extracted with ethyl acetate (2 x 150 mL). The combined
organic extracts were washed with 2 N potassium hydrogen
sulfate (200 mL) , saturated sodium bicarbonate (2 x 150 mL) ,
brine (150 mL) and dried over magnesium sulfate. Removal of
solvent in vacuo gave (R)-(+)-l-Boc-3-pyrrolidinol (4.21 g,
98%) as a yellow oil.
1H-NMR (CDC13)
l-Boc-3-pyrrolidinone.
Prepared from (R)-(+)-1-Boc-3-pyrrolidinol using the
Dess-Martin oxidation (Dess, D. B.; Martin, J. C; J. Am.
Chem. Soc, 1991, 113, 7277) (85%) .
1H NMR (CDCI3)
1-(4-Methoxybenzyl-D-phenylglycinyl)-4-(l-Boc-3-pyrrolidinyl) -
piperazine.
Prepared from 1-(4-methoxybenzyl-D-phenyl-
glycinyl)piperazine trifluoroacetate and l-Boc-3-pyrrolidinone
using Method I-A (69%) .
1H NMR (CDCI3)
1- (4-Methoxybenzoyl-D-phenylglycinyl)-4-(3-pyrrolidinyl)-
piperazine Trifluoroacetate.
Prepared from 1-(4-methoxybenzyl-D-phenylglycinyl)-4-(l-Boc-3-
pyrrolidinyl)piperazine using Method H-A.
-1H NMR (CD3OD)
Methods for Examples 32 - 33
Using Method I-A (but using sodium triacetoxyborohydride
in 1,2-dichloroethane), the title compounds were prepared from
1- (4-methoxybenzoyl-D-phenylglycinyl) -4- (3-pyrrolidinyl) -
piperazine trifluoroacetate and the indicated aldehyde or
ketone.
Example 32
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(l-methylpyrrolidin-3-
yl)piperazine.
Prepared from paraformaldehyde (20%).
1H-NMR(CDC13)
Example 33
1- (4-Methoxybenzoyl-D-phenylglycinyl)-4-(1-isopropyl-
pyrrolidin-3-yl)piperazine.
Prepared from acetone (59%) .
1H-NMR(CDCl3)
Methods for Examples 34 - 46
Unless otherwise indicated, the products of Examples
34-46 were obtained from l-(4-methoxybenzoyl-D-phenyl-
glycinyl)piperazine and the indicated aldehyde or ketone using
Method I-A.
Example 34
1- (4-Methoxybenzoyl-D-phenylglycinyl) -4- (2-pyridylmethyl) -
piperazine.
Prepared from 2-pyridinecarboxaldehyde (4 8%).
1H-NMR
IS-MS, m/e 444.9 (M+l)
Analytical RPHPLC, Method A, RT = 21.70 min (100%)
Example 35
1- (4-Methoxybenzoyl-D-phenylglycinyl) -4- (3-pyridylmethyl) -
piDerazine.
Prepared from 3-pyridinecarboxaldehyde (42%) .
1H-NMR
IS-MS, m/e 444.9 (M+l)
Analytical RPHPLC, Method A, RT = 17.84 min (99%)
Example 3 6
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(4-pyridylmethyl)-
piperazine.
Prepared from 4-pyridinecarboxaldehyde (45%) .
1H-NMR
IS-MS, m/e 444.9 (M+l)
Analytical RPHPLC, Method A, RT = 18.36 min (99%)
Example 37
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(3-pentyl)piperazine.
Prepared from 3-pentanone (88%) .
1H-NMR
IS-MS, m/e 424.0 (M+l)
Analytical RPHPLC, Method A, RT = 23.62 min (100%)
Example 38
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-cyclopentylpiperazine.
Prepared from cyclopentanone (95%).
1H-NMR
IS-MS, m/e 422.0 (M+l)
Analytical RPHPLC, Method A, RT = 20.76 min (100%)
Example 3 9
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(4-methylcyclohexyl)-
piperazine.
Prepared from 4-methyleyelohexanone (46%) .
1H-NMR
IS-MS, m/e 450.0 (M+l)
Analytical RPHPLC, Method A, RT = 27.07 min (isomer 1), 27.74
min (isomer 2).
Example 40
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(tetrahydrothiopyxan-
4-yDpiperazine.
Prepared from tetrahydro-4H-thiopyran-4-one (86%).
1H-NMR
IS-MS, m/e 453.9 (M+l)
Analytical RPHPLC, Method A, RT = 22.96 min (100%)
Example 41
1- (4-Methoxybenzoyl-D-phenylglycinyl) -4- (2-indanyl)piperazine.
Prepared from 2-indanone (92%).
1H-NMR
IS-MS, m/e 469.9 (M+l)
Analytical RPHPLC, Method A, RT = 26.32 min (100%)
Example 42
1- (4-Methoxybenzoyl-D-phenylglycinyl) -4-benzylpiperazine.
Prepared from benzaldehyde (87%).
1H-NMR
IS-MS, m/e 444.0 (M+l)
Analytical RPHPLC, Method A, RT = 25.78 min (96%)
Example 43
1-(4-Metb.oxybenzoyl-D-phenylglycinyl)-4-(cyclohexyl-
methyl)piperazine.
Prepared from cyclohexan^carboxaldehyde (86%) .
1H-NMR
IS-MS, m/e 450.2 (M+l)
Analytical RPHPLC, Method A, RT = 28.07 min (94%)
Example 44
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(4-heptyl)piperazine.
Prepared from 4-heptanone (89%).
1H-NMR
IS-MS, m/e 452.0 (M+l)
Analytical RPHPLC, Method A, RT = 2 9.62 min (94%)
Example 45
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(4-pyranyl)piperazine.
Prepared from pyran-4-one (95%).
1H-NMR
IS-MS, m/e 437.9 (M+l)
Analytical RPHPLC, Method A, RT = 18.46 min (97.5%)
Example 46
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-cyclohexylpiperazine.
Prepared from cyclohexanone (quantitative).
1H-NMR
IS-MS, m/e 436.0 (M+l)
Analytical RPHPLC, Method A, RT = 23.43 min (100%)
Examples 47-50
Preparation of Starting Materials
1-(Cbz-D-Phenylglycinyl)piperazine.
Prepared from 1-(Cbz-D-phenylglycinyl)-4-Boc-piperazine
using Method H-A. The crude product was dissolved in ethyl
acetate and washed with satd aq. NaHCO3, followed by brine,
then dried with MgSO4, filtered and concentrated in vacuo
(85%).
1H-NMR
IS-MS, m/e 354.2 (M+l)
Analysis for C20H23N3O3•0.2 H2O;
Calcd: C, 67.28; H, 6.61; N, 11.77;
Found: C, 67.10; H, 6.46; N, 11.63.
1-(Cbz-D-phenylglycinyl)-4-(l-methylpiperidin-4-yl)piperazine.
Prepared from (Cbz-D-phenylglycinyl)piperazine and
l-methylpiperidin-4-one using Method I-A (but using sodium
triacetoxyborohydride in 1,2-dichloroethane)(49%).
1H-NMR
IS-MS, m/e 451.3 (M+l)
Analysis for C26H34N4O3:
Calcd: C, 69.31; H, 7.61; N, 12.43;
Found: C, 69.36; H, 7.71; N, 13.14.
l-D-Phenylglycinyl-4-(l-methylpiperidin-4-yl)piperazine
Dihydrochloride.
To a stirring suspension of 5% Pd/C (0.6 g) in ethanol
(25 mL) under nitrogen was added a solution of 1-(Cbz-D-
phenylglycinyl)-4-(l-methylpiperidin-4-yl)piperazine (2.6 g,
5.77 mmol) and acetic acid (1.6 mL) in ethanol (50 mL) . The
flask was placed under vacuum and the atmosphere was replaced
with hydrogen (balloon) . After 4 h, diatomaceous earth was
added and the mixture was filtered through a pad of
diatomaceous earth and concentrated in vacuo. The residue was
dissolved in ethyl acetate and HCl gas was bubbled through the
stirring solution to precipitate the dihydrochloride salt.
The mixture was filtered and the solid was dried in vacuo to
give 2.6 g (quantitative) of the title compound.
1H-NMR
IS-MS, m/e 317.3 (M+l)
1-Boc-D-Phenylglycinyl-4-(1-methylpiperidin-4-yl) piperazine
Boc-D-Phg-OH (40.0 g, 159.2 mmol) and 1-(1-methyl-
piperidin-4-yl)piperazine (32.1 g, 175.1 mmol) were slurried
in anhydrous dichloromethane (1.5 L) under N2. The mixture
was then cooled to -15 °C in an ice/MeOH bath. Triethylamine
(26.6 mL, 191.0 mmol) was added slowly, maintaining the
temperature at -15 °C, followed by slow addition of diethyl
cyanophosphonate (29.0 mL, 191.0 mmol), again maintaining temp
at -15 °C. The reaction mixture was allowed to warm to room
temperature overnight. The reaction was then quenched with
the addition of satd NaHCO3 (500 mL), and the layers were
separated. The aqueous layer was then extracted with
dichloromethane (3 x 1 L). The organic layers were combined,
dried over Na2SO4, filtered and concentrated in vacuo to give
a crude oil. Purification using (Biotage) Flash
Chromatography with 7.5% (2 M NH3 in MeOH) in THF gave 53.6 g
(81%) of the title compound.
1H NMR (DMSO-d6) d 7.33 (m, 5 H), 7.12 (d, J= 8.1 Hz, 1 H),
5.53 (d, J = 8.1 Hz, 1 H), 3.31 (m, 5 H), 2.72 (d, J = 11.3
Hz, 2 H), 2.3 (m, 3 H), 2.09 (s, 3 H), 2.03 - 1.86 (m, 2 H),
1.76 (dt, J = 9.7, 1.8 Hz, 2 H) , 1.56 (m, 2 H) , 1.36 (s, 9 H) .
IS-MS, m/e 416.27 (M+l).
Chiral HPLC indicated no racemization had occurred.
l-D-Phenylglycinyl-4-(l-methylpiperidin-4-yl)piperazine
Trihydrochloride.
l-Boc-D-phenylglycinyl-4-(l-methylpiperidin-4-yl)-
piperazine (49.6 g, 119.1 mmol) was dissolved in anhydrous
MeOH (1 L) and HC1 (gas) was bubbled through the solution for
2 h 15 min, noting the formation of a white precipitate. The
solvents were removed in vacuo to give 48.3 g (95%) of the
title compound as an off-white foam.
1H NMR (DMSO-d6) d 12.08 (bs, 1 H), 11.03 (bs, 1 H), 8.92 (bs,
2 H) , 8.79 (bs, 1 H) , 7.54 (m, 2 H) , 7.47 (m, 3 H) , 5.66 (s, 1
H), 4.49 (m, 1 H), 4.26 (bd, 1 H), 3.91 (bs, 2 H), 3.5 - 2.8
(m, 9 H), 2.69 (s, 3 H), 2.4 - 1.8 (m, 4 H). IS-MS, m/e
316.24 (M+l).
General Procedure: Except as otherwise described, the product
of each of Examples 47-50 was prepared from 1-(D-
phenylglycinyl)-4-(l-methylpiperidin-4-yl)piperazine
dihydrochloride and the indicated acid using Method I-C (with
EDCI in place of DCC).
Example 47
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(l-metbylpiperidin-4-
yl)piperaz ine.
Prepared from 4-methoxybenzoic acid (19%).
1H-NMR
IS-MS, m/e 451.0 (M+l)
Analytical RPHPLC, Method A, RT = 16.76 min (100%)
Example 47a
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
yDpiperazine Dihydrochloride.
Prepared from 1- (4-methoxybenzoyl-D-phenylglycinyl) -4- (1-
methylpiperidin-4-yl)piperazine using Method I-D {but using
dichloromethane as the initial solvent).
1H NMR
Analysis for C28H28C1N5O2•2.0 HC1 0.5 H2O:
Calcd: C, 58.64; H, 7.00; N, 10.22;
Found: C, 58.92; H, 6.79; N, 10.19.
HPLC Analysis (Method A): 100% tr = 17.14 min.
Example 47 (Alternative Synthesis)
1-(4-Methoxybenzoyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
yl)piperazine.
l-D-Phenylglycinyl-4-(l-methylpiperidin-4-yl)piperazine
trihydrochloride (5.0 g, 11.7 mmol) was slurried in anhydrous
dichloromethane (100 mL). To the slurry was added
triethyamine (6.9 mL, 49.3 mmol), causing the solid to go into
solution after approximately 15 min. p-Anisoyl chloride (2.1
mL, 14.1 mmol) was added, and the reaction stirred for 1 h.
The reaction was quenched with the addition of water (100 mL) ,
and the layers were separated. The aqueous layer was
extracted with dichloromethane (3 x 100 mL) . The aqueous
-layers were combined, dried over Na2SO4, filtered and
concentrated. The crude material was purified twice using
(Biotage) Flash Chromatography, eluting with 5% (NH3 in MeOH)
in dichlormethene to give 1.4 g (26%) of the title compound.
1H NMR (DMSO-d6) d 8.65 (d, J = 7.7 Hz, 1 H) , 7.88 (d, J = 8.8
Hz, 2 H), 7.3 5 (m, 5 H) , 6.97 (d, J = 8.8 Hz, 1 H) , 6.4 0 (d, J
7.7 Hz, 1 H) , 3.80 (s, 3 H) , 3.48 (m, 3 H) , 2.72 (d, J = 11.3
Hz, 2 H) , 2.39 (m, 3 H) , 2.09 (s, 3 H) , 2.02 (m, 2 H) , 1.77
(dt, J = 1.8, 10.2 Hz, 2 H) , 1.59 (d, J = 11.0 Hz, 2 H) , 1.30
(m, 2 H) .
IS-MS m/e 450.26 (M+l).
[a]D20 = -87.62 (c=0.02, MeOH).
Analysis for C26H34N4O3 H2O:
Calcd: C, 66.64/ H, 7.74; N, 11.96;
Found: C, 66.79; H, 7.41; N, 11.94.
Example 48
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
yDpiperazine.
Prepared from indole-6-carboxylic acid (65%) .
1H-NMR
IS-MS, m/e 460.2 (M+l)
Analytical RPHPLC, Method A, RT = 16.68 min (100%)
Example 48a
1- (Indole-6-carbonyl-D-phenylglycinyl) -4- (l-methylpiperidin-4-
yDpiperazine Dihydrochloride.
May be prepared from 1-(indole-6-carbonyl-D-phenyl-
glycinyl)-4-(l-methylpiperidin-4-yl)piperazine using Method I-
D (but using dichloromethane as the initial solvent) .
Example 48 (Alternative Synthesis) ,
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
yl)piperazine.
Indole-6-carboxylic acid (16.0 g, 99.3 mmol) and
1 -D-phenylglycinyl-4-(1-methylpiperidin-4-yl) piperazine
trihydrochloride (42.3 g, 99.3 mmol) were slurried in
anhydrous dichloromethane (1 L) under N2. The mixture was
then cooled to -15 °C in an ice/MeOH bath. Triethyamine (58.1
mL, 416.9 mmol) was added slowly, maintaining the temperature
at -15 °C, followed by slow addition of diethyl
cyanophosphonate (18.1 mL, 119.1 mmol), maintaining the
temperature at -15 °C. The reaction mixture was allowed to
warm to room temperature overnight. The reaction was then
quenched with the addition of satd NaHCO3 (500 mL) , and the
layers were separated. The aqueous layer was then extracted
with dichloromethane (3 x 500 mL) . The organic layers were
combined, dried over Na2SO4, filtered and concentrated to give
a crude oil. Purification was performed using (Biotage) Flash
Chromatography, eluting with 8.3% (2 M NH3 in MeOH) in CHCl3 .
The product containing fractions were combined and
concentrated in vacuo to give 45.1 g (99%) of the title
compound.
1H NMR (DMSO-d6) d 11.35 (s, 1 H), 8.65 (d, J » 7.7 Hz, 1 H),
7.98 (s, 1 H) , 7.60 - 7.45 (m, 5 H) , 7.40 - 7.25 (m, 3 H) ,
6.48 (t, J= 2.0 Hz, 1 H), 6.09 (d, J= 7,7 Hz, 1H), 3.5 (m,
3 H) , 2.72 (d, J = 11.3 Hz, 2 H) , 2.40 (m, 2 H) , 2.09 (s, 3
H) , 2.05 (m, 2 H) , 1.77 (dt, J = 1.1, 10.2 Hz, 2 H) , 1.5 9 (d,
J= 11.3 Hz, 2 H), 1.31 (m, 2 H).
13C NMR (DMSO-d6) d 168.0, 166.4, 138.0, 135.1, 129.9, 128.4,
128.2, 128.0, 127.6, 126.6, 119.4, 118.1, 111.5, 101.2, 79.1,
60.6, 54.7, 53.7, 48.5, 48.3, 45.8, 45.4, 42.2, 27.7, 27.6.
IS-MS, m/e 459.26 (M+l).
[a]D20 = -73.08 (c=0.02, MeOH).
A portion of the free base was isolated from a chloroform
- ethyl acetate solvent system as crystalline material which
was birefringent by microscopy. From DSC and TGA, the
material was found to be a solvate containing 0.5 mol
chloroform per mol of free base. The chloroform solvate was
found to have a broad endotherm about 148-158 °C, followed by a
sharper endotherm (peak at 194.4 °C) as the melting point of
the desolvated free base.
Example 48a (Alternative Synthesis)
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
yl)piperazine Hydrochloride.
To a solution of 1-(indole-6-carbonyl-D-phenylglycinyl)-
4-(l-methylpiperidin-4-yl)piperazine (14.5 g, 31.6 mmol) in
anhydrous dichloromethane (3 00 mL) and anhydrous MeOH (150 mL)
at 0 °C was added HCl in Et2O (32.2 mL, 32.2 mmol) . After
approximately 5 min, the solvents were removed in vacuo to
give 15.1 g (96%) of the title compound.
1H NMR (DMSO-d6) d 11.40 (s, 1 H), 10.3 (bs, 1 H), 8.68 (m, 1
H), 7.99 (s, 1 H), 7.6 - 7.4 (m, 5 H), 7.4 - 7.3 (m, 3 H),
6.48 (s, 1 H), 6.11 (d, J = 7.3 Hz, 1 H), 4.08 (bs, 1 H), 3.6
- 1.5 (bm, 15 H), 2.66 (s, 3 H).
IS-MS, m/e 459.26 (M+l).
[a]D20 = -83.67 (c=0.01, MeOH).
Analysis for C27H33N5O2•1.1 HCl•1.7 H2O:
Calcd: C, 61.03; H, 7.30; N, 13.18; Cl, 7.34;
Found: C, 60.95; H, 6.91; N, 13.03; Cl, 7.0C.
The product prepared by both the method of Example 4 8a
and Example 48a (Alternative Synthesis) was found to be the
mono-hydrochloride salt and to be amorphous. Analysis by
microscopy showed glassy non-birefringent particles; and
analysis by DSC failed to reveal a melting point, in agreement
with amorphous material. Using a microbalance flow system,
the original material was cycled through a vapor pressure
isotherm determination, where the material deliquesced, then
allowed to deydrate. Upon dehydration, there were formed
crystals which were birefringent by microscopy; and a melting
point of about 174 °C was demonstrated for the newly
crystallized, hygroscopic material.
Example 48b
1-(Indole-6-carbonyl-D-phenylglycinyl)-4-(l-methylpiperidin-4-
yl)piperazine Difumarate.
The difumarate salt is conveniently prepared by
dissolving the free base in methanol or 95% ethanol and
warming to about 50 °C (for example at a concentration of 460
mg in 15 mL) . Two molar equivalents of fumaric acid (for
example 232.2 mg) are then added (for example, as a 0.25 M
solution in methanol or as a suspension in 3 mL 9 5% ethanol) .
Following cooling and crystallization, and isolation and
drying, the product is obtained as thin crystalline needles,
with a sharp melting point at about 213 °C by DSC.
Example 49
1-(3-Methylindole-6-carbonyl-D-phenylglycinyl)-4-
(l-methylpiperidin-4-yl)piperazine.
Prepared from 3-methylindole-6-carboxylic acid (50%) .
1H-NMR
IS-MS, m/e 474.3 (M+l)
Analytical RPHPLC, Method A, RT = 22.20 min (98%)
Example 50
1-(3-Chloroindole-6-carbonyl-D-phenylglycinyl) -4-
(l-methylpiperidin-4-yl) piperazine.
Prepared from 3-chloroindole-6-carboxylic acid (76%).
1H-NMR
IS-MS, m/e 493.9 (M+l)
Analytical RPHPLC, Method A, RT = 22.66 min (100%)
Example 51
1- (3-Chloroindole-6-carbonyl-D-phenylglycinyl)-4-
(4-piperidinylmethyl) piperazine Dihydrochloride.
Preparation of Starting Materials:
1-(l-Boc-piperidin-4-ylmethyl)piperazine.
To a stirring solution of l-Boc-piperidine-4-carbox-
aldehyde (2.4 g, 11.3 mmol) in THF (60 mL) and acetonitrile
(15 mL) was added piperazine (4.85 g, 56.3 mmol). After
stirring for 5 h, sodium triacetoxyborohydride (2.87 g, 13.5
mmol) was added and the reaction was allowed to stir
overnight. The next morning, the solvents were removed by
rotary evaporation and the residue was dissolved in ethyl
acetate, washed twice with satd aq. NaHCO3, followed by water,
then dried over MgSO4, filtered and concentrated in vacuo.
The residue was then chromatographed over silica gel, eluting
with a step gradient of 2% through 15% (2 N ammonia/methanol)
in dichloromethane. The product containing fractions were
combined and concentrated in vacuo to give 4.03 g (48%) of the
title compound.
1H-NMR
IS-MS, m/e 284.3 (M+l)
1- (Cbz-D-Phenylglycinyl)-4-(l-Boc-piperidin-4-ylmethyl)-
piperazine.
Prepared from Cbz-D-phenylglycine and 1-(1-Boc-piperidin-
4-ylmethyl)piperazine using Method C-A. The title compound
was purified by chromatography over silica gel, eluting with a
step gradient of 1% to 3% (2 N ammonia/methanol in
dichloromethane.
1H-NMR
IS-MS, tn/e 551.3 (M+l)
1-(D-Phenylglycinyl)-4-(l-Boc-piperidin-4-ylmethyl)piperazine.
Prepared from 1-(Cbz-D-phenylglycinyl)-4-(1-Boc-
piperidin-4-ylmethyl)piperazine using Method F-A.
1H-NMR
IS-MS, ,m/e 417.8 (M+l)
1-(3-Chloroindole-6-carbonyl-D-phenylglycinyl)-4-
(4-piperidinylmethyl)piperazine Dihydrochloride.
Prepared from 3-chloroindole-6-carboxylic acid and 1-(D-
phenylglycinyl)-4-(l-Boc-piperidin-4-ylmethyl) piperazine using
Methods I-C, D-B, and I-D (using dichloromethane in place of
ether/dichloromethane as an initial solvent).
1H-NMR
IS-MS, m/e 494.2 (M+l)
Analysis for C27H32N5O2Cl 2.2 HC1•3.0 H2O:
Calcd: C, 51.61; H, 6.45; N, 11.15; Cl, 18.06;
Found: C, 51.40; H, 6.12; N, 11.02; Cl, 17.80.
Analytical RPHPLC, Method A, RT = 20.59 min (100%)
Example 52
1- (3-Methylindole-6-carbonyl-D-phenylglycinyl) -4-
(4-piperidinylmethyl)piperazine Dihydrochloride.
Prepared from 3-methylindole-6-carboxylic acid and 1-(D-
phenylglycinyl)-4-(l-Boc-piperidin-4-ylmethyl)piperazine using
Methods I-C, D-B, and I-D (using dichloromethane in place of
ether/dichloromethane as an initial solvent).
1H-NMR
IS-MS, m/e 474.2 (M+l)
Analysis for C28H35N5O2 2.3 HC1 4.0 H2O:
Calcd: C, 53.42; H, 7.25; N, 11.13; Cl, 12.95;
Found: C, 53.14; H,.6.71; N, 10.99; Cl, 13.12.
Analytical RPHPLC, Method A, RT = 20.23 tnin (100 %)
Example 53
1-[4-Chlorobenzoyl-D-phenylglycinyl]-4-benzylpiperazine
Trifluoroacetate.
Boc-D-phenylglycine (753 mg, 3 ramol), TBTU (2-(1H-(benzo-
triazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate)
(963.3 mg, 3 mmol), diisopropylethylamine (894 mg, 6 mmol) and
4-benzylpiperazine (525 mg, 3 mmol) were combined in DMP (10
mL) and stirred overnight. The reaction mixture was taken
into dichloromethane (25 mL) washed with water (50 mL) and
evaporated to dryness.
The residue was treated with TFA (5 mL) for 1 h and the
excess TFA evaporated in vacuo. Triethylamine (1 mL) was
added and evaporated in vacuo. This mixture was then divided
into three equal parts. One part was then treated with a
mixture of 4-chlorobenzoic acid (156.5 mg, 1 mmol), HOBt
(148.5 mg, 1.1 mmol) and EDCI (191 mg, 1 mmol) in DMF (3 mL)
that had been stirred for 5 min. The reaction mixture was
stirred overnight, diluted with water and acetonitile, and
applied directly for purification by preparative RPHPLC to
give the title compound, (12C mg) .
1H-NMR
By similar methods to those described in Example 53 the
following compounds were prepared:
Example 54
1- [4-Chlorobenzoyl-D-phenylglycinyl] -4- (2-phenethyl)piperazine
Trifluoroacetate.
1H-NMR
MS MALDI TOF M+l =462
Example 55
1- [4-Chlorobenzoyl-D-phenylglycinyl] -4- (cyclohexylmethyl) -
piperazine Trifluoroacetate.
1H-NMR
MS MALDI TOF M+l = 454
Example 56
1- [Indole-6-carbonyl— D-phenylglycinyl] -4- [2- (thiazol-2-yl) -
ethyl]piperazine Hydrochloride.
Prepared from l- (D-phenylglycinyl) -4- [2- (thiazol-2-yl) -
ethyl] piperazine trihydrochloride and indole-6-carboxylic acid
using methods substantially equivalent to Method I-C followed
by Method I-D. ,
Melting- Point = 135-142 °C with decomposition.
!H NMR (CD3OD).
APCI-MS, m/e = 474 (C26H27N5O2ST1) .
HPLC Analysis (Method B): 98.8% tr = 14.2 min.
Example 57
(No Example 57)
Example 58a
1- [Indole-6-carbonyl— D-phenylglycinyl] -4- [2- (3 -f luoropyridin-
4-yl)ethyl]piperazine.
Prepared from 1-(D-phenylglycinyl)-4 - [2-(3-f luoropyridin-
4-yl)ethyl]piperazine and indole-6-carboxylic acid using a
method substantially equivalent to Method I-C (66%) .
1H NMR (CDCl3).
APCI-MS, m/e = 486 (C28H28FN5O2+1).
Example 58b
1-[Indole-6-carbonyl— D-phenylglycinyl]-4-[2-(3-fluoropyridin-
4-yl)ethyl]piperazine Hydrochloride.
Prepared from 1-(indole-6-carbonyl-D-phenylglycinyl)-4-
[2-(3-fluoropyridin-4-yl)ethyl]piperazine using a method
substantially equivalent to Method I-D (89%)
[a]25D -98.8° (c 0.30, methanol)
Melting Point = 135-145 °C with decomposition.
lH NMR (CD3OD).
APCI-MS, m/e = 486 (C28H28FN5O2+1).
TLC Rf = 0.44 (7:3 CH2Cl2:CMA)
Analysis for C28H31N3O4 1.25 HC1 1.2 H2O:
Calcd: C, 60.84; H, 5.77; N, 12.67; Cl, 8.02;
Found: C, 61.14; H, 5.86; N, 12.34; Cl, 7.88.
HPLC Analysis (Method B): 98.2% tr = 13.2 min.
Example 59a
1-[Indole-6-carbonyl- D-phenylglycinyl]-4-[2-(2-cyanopyridin-
4-yl)ethyl]piperazine.
Method I-E
1-(D-Phenylglycinyl)-4- [2-(2-cyanopyridin-4~ylethyl) -
piperazine trihydrochloride (580 mg, 1.26 mmol), indole-6-
carboxylic acid (205 ing, 1.26 mmol), HOBt (171 mg, 1.26 mmol),
and triethylamine (0.88 mL, 6.9 mmol) were dissolved in DMF
(20 mL). To this solution, DCC (390 mg, 1.89 mmol) was added,
and the mixture stirred at room temperature overnight. Ethyl
acetate (100 mL) and heptane (20 mL) were added and solids
removed by filtration. The solvents were removed under vacuum
and residue re-dissolved in toluene/ethyl acetate (200 mL,
1:1) and solids removed by filtration. The filtrate was
washed with water and brine, dried (Na2SO4), filtered, and
concentrated under vacuum to provide crude product (800 mg).
The crude product was purified by chromatography (SiO2,
1000:10:1 - 250:10:1 CH2Cl2:methanol:concentrated ammonium
hydroxide) to provide the sub-titled compound (443 mg, 71%).
lH NMR (CDC13).
TLC = 0.3 (200:10:1, CH2Cl2:methanol:concentrated ammonium
hydroxide)
Example 59b
1-[Indole-6-carbonyl— D-phenylglycinyl]-4-[2-(2-cyanopyridin-
4-yl)ethyl]piperazine Hydrochloride.
Prepared from 1-(indoyl-6-carbonyl-D-phenylglycinyl)-4-
[2-(2-cyanopyridin-4-yl)ethyl]piperazine using methods
substantially equivalent to those described in Method I-D,
(96%).
[a]25D -92.0° (c 0.27, methanol)
Melting Point = 156-169 °C
IR(ATR).
1H NMR (CD3OD).
APCI-MS, m/e = 493 (C29H28N6O2+D.
Analysis for C28H31N3O4•1.1 HC1• 0.9 H2O:
Calcd: C, 63.44; H, 5.68; N, 15.31; Cl, 7.10;
Found: C, 63.53; H, 5.68; N, 15.41; Cl, 6.88.
HPLC Analysis (Method B): 98.9% tr = 15.2 min.
Example 60
1- [4-Methoxybenzoyl— D,L-(2-ch.lorophenyl)glycinyl]-4-
(1-methylpiperidin-4-yl)piperazine Hydrochloride.
Prepared from 1-[D,L-(2-chlorophenyl)glycinyl] -4-
(l-methylpiperidin-4-yl)piperazine and p-anisoyl chloride
using procedures substantially equivalent to those described
in Method I-B, using dichloromethane for aqueous dioxane and
TEA for K2CO3, followed by Method I-D.
1H NMR
IS-MS, m/e 485.3 (M+l)
Analysis for C27H32N5O2Cl 2.2 HCl 2.0 H20:
Calcd: C, 53.14; H, 6.31; N, 11.48; Cl, 18.59;
Found: C, 53.04; H, 5.86; N, 11.36; Cl, 18.13.
HPLC Analysis (Method A): 100% tr = 19.78 min.
Example 61
1- [4-Methoxybenzoyl-D- (2-chlorophenyl) glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine Hydrochloride.
1- [4-Methoxybenzoyl-D, L- (2-chlorophenyl) glycinyl] -4-
(l-methylpiperidin-4-yl)piperazine (8.20 g, 18.16 mmol) was
divided into 2 g lots and each lot was dissolved in a mixture
of chloroform (1.0 mL) , isopropanol (13 mL) and heptane (26
mL). These samples were then individually chromatographed
using preparative chiral HPLC (Chiralcel OD, 8 x 34 cm,
eluting with 35% isopropanol/65% heptane with 0.4% DMEA for 21
min at a flow rate of 350 mL/min) . Analytical HPLC of the the
racemic mixture (Chiralcel OD, 4.6 x 250 mm, eluting with 35%
isopropanol/65% heptane with 0.4% DMEA, 1.0 mL/min, UV
detection at 2 60 nm) revealed two peaks, baseline resolved.
The fractions from the preparative HPLC runs containing the
peak with the shorter retention time were combined and
concentrated in vacuo to give 3.71 g of isomer 1. The
fractions containing the later running isomer were combined
and concentrated to give 3.80 g of isomer 2. Biological
evaluation of the two samples revealed isomer 1 to be over ten
times more potent than isomer 2 and on that basis, isomer 1
was tentatively assigned as the D-isomer. Isomer 1 was then
chromatographed over silica gel (Biotage Quad 12/25 System, 25
mm KP-Sil [32-63um particle size] columns, eluting with a
gradient of 0-6% 2N ammonia/methanol in dichloromethane) and
the product containing fractions were combined and
concentrated. The residue was then redissolved in
dichloromethane and to this stirring solution was added 1 M
HCl in diethyl ether (4.33 mL, 4.33 mmol). The precipitate
was filtered and dried in vacuo to give 2.3 g (49%) of the
title compound.
1H NMR
IS-MS, m/e 485.3 (M+l)
Analysis for C26-H33N4O3Cl 1.3 HCl • 0.5 H20:
Calcd: C, 57.68; H, 6.57; N, 10.35; Cl, 15.06;
Found: C, 57.42; H, 6.76; N, 10.06; Cl, 14.69.
Example 62
1-[Indole-6-carbonyl— D,L-(2-chlorophenyl)glycinyl] -4-
(1-methylpiperidin-4-yl)piperazine Dihydrochloride.
Method I-F
To a stirring solution of D,L-(2-chlorophenyl)glycinyl]-
4-(l-methylpiperidin-4-yl)piperazine (0.458 g, 1.31 mmol) in
dichloromethane (5 niL) and DMF (2 mL) was added indole-6-
carboxylic acid (0.233 g, 1.44 mmol). The solution was cooled
to 0 °C and DEPC (0.218 mL; 1.44 mmol) was added. After 24 h,
the solution was concentrated in vacuo and the residue was
dissolved in 5% acetic acid/methanol and loaded onto an SCX
column. The column was washed with methanol, and then the
compound was eluted with 50% (2 N ammonia/methanol) in
dichloromethane. The product containing fractions were
combined and concentrated in vacuo. The residue was then
chromatographed over silica gel, eluting with a gradient of 0-
5% (2 N ammonia/methanol) in dichloromethane. Again, the
product containing fractions were combined and concentrated in
vacuo to give 0.6 g of off-white solid. The HCl salt was then
prepared using Method I-D to give 290 mg (39%) of the title
compound.
1H NMR
IS-MS, m/e 494.2 (M+l)
Analysis for C26H33N4O3C1.2 HCl 0.5 H2O:
Calcd: C, 54.38; H, 6.35; N, 9.76; Cl, 19.76;
Found: C, 54.08; H, 6.12; N, 9.59; Cl, 19.44.
HPLC Analysis (Method A): 100% tr = 21.59 min.
Example 63
1- [Indole-6-carbonyl-D-(2-chlorophenyl)glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine Dihydrochloride.
1-[Indole-6-carbonyl-D,L-(2-chlorophenyl)glycinyl]-4-(1-
methylpiperidin-4-yl)piperazine (18.8 mmol theoretical) was
divided into 0.5 g lots and each lot was dissolved in a
mixture of isopropanol (5 tnL) and heptane (20 mL) . These
samples were then individually chromatographed using
preparative chiral HPLC (Chiralcel OD, 8 x 34 cm, eluting with
30% iso-propanol/70% heptane with 0.2% DMEA for 14 min at a
flow rate of 370 mL/min). Analytical HPLC of the racemic
mixture (Chiralcel OD, 4.6 x 250 mm, eluting with 30%
isopropanol/70% heptane with 0.2% DMEA, 1.0 mL/min, UV
detection at 260 nm) revealed two peaks, baseline resolved.
The fractions from the preparative HPLC runs containing the
peak with the shorter retention time were combined and
concentrated in vacuo to give 2.8 g of isomer 1. The
fractions containing the later running isomer were combined
and concentrated to give 2.80 g of isomer 2. Biological
evaluation of the two samples revealed isomer 1 to be about
100 times more potent than isomer 2; and, on thar basis,
isomer 1 was tentatively assigned as the D-isomer. Isomer 1
(2.6 g) was then redissolved in dichloromethane, and to this
stirring solution was added 1 M HCl in diethyl ether (5.26 mL,
5.26 mmol). The precipitate was filtered and dried in vacuo
to give 2.4 g (48%) of the title compound.
1H NMR
IS-MS, m/e 494.0 (M+l)
Analysis for C27H32N5O2Cl 2.1 HC1 0.7 H20:
Calcd: C, 59.31/ H, 6.36; N, 12.81; Cl, 13.62;
Found: C, 59.57; H, 6.41; N, 12.42; Cl, 13.31.
Example 64
1- [Indole-6-carbonyl-D,L-(quinolin-8-yl)glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine Dihydrochloride.
Prepared from indole-6-carboxylic acid and D,, L-(quinolin-
8-yl) glycinyl]-4-(l-methylpiperidin-4-yl)piperazine using
procedures substantially equivalent to those described in
Method I-C followed by Method I-D. The final product was
purified by preparative RPHPLC (Vydac C18, 90% A through 65%
A; A=0.01% aq. HC1, B=acetonitrile).
1H NMR
IS-MS, m/e 511.1 (M+l)
Analysis for C30H34N6O2 1.9 HC1-3.0 H2O:
Calcd: C, 56.84; H, 6.66; N, 13.26; Cl, 10.63;
Found: C, 56.79; H, 6.81; N, 13.12; Cl, 10.62.
HPLC Analysis (Method A) : 98.6% tr = 17.84 min.
Example 65
1- [3-Chloroindole-6-carbonyl-D,L- (quinolin-8-yl) glycinyl] -4-
(l-methylpiperidin-4-yl)piperazine Hydrochloride.
Prepared from 3-chioroindole-6-carboxylic acid and
D,L- (quinolin-8-yl) glycinyl] -4- (l-methylpiperidin-4-yl) -
piperazine using procedures substantially equivalent to those
described in Method I-C followed by Method I-D.
1H NMR
IS-MS, m/e 545.0 (M+l)
Analysis for C30H33N6O2Cl 1.6 HC1•1.5 H20:
Calcd: C, 57.15; H, 6.01; N, 13.33; Cl, 14.62;
Found: C, 56.86; H, 5.64; N, 13.02; Cl, 14.37.
HPLC Analysis (Method A) : 100% tr = 25.08 min.
Example 66
1-[3-Methylindole-6-carbonyl-D,L-(quinolin-8-yl)glycinyl]-4-
(l-methylpiperidin-4-yl)piperazine Trihydrochloride.
Prepared from 3-methylindole-6-carboxylic acid and
D,L-(quinolin-8-yl)glycinyl]-4-(l-methylpiperidin-4-yl)-
piperazine using procedures substantially equivalent to those
described in Method I-C followed by Method I-D.
1H NMR
IS-MS, m/e 525.1 (M+l)
Analysis for C31H36N6O2•3.0 HCl-2.6 H2O:
Calcd: C, 54.68; H, 6.54; N, 12.34; Cl, 15.62;
Found: C, 54.41; H, 6.25; N, 12.00; Cl, 15.99.
HPLC Analysis (Method A): 99% tr = 23.06 min.
Example 67
1-[4-Methoxybenzoyl-D,L-(2-trifluoromethylphenyl)glycinyl]-4-
(l-methylpiperidin-4-yl)piperazine Hydrochloride.
Prepared from using procedures substantially equivalent
to those described in Method I-C followed by I-D.
1H NMR
IS-MS, m/e 519.0 (M+l)
HPLC Analysis (Method A) : 98% tr = 20.18 min.
Example 68
1- [4-Methoxybenzoyl-D-(2-trifluoromethylphenyl)glycinyl]-4-
(l-methylpiperidin-4-y3)piperazine Dihydrochloride.
1- [4-MethoxybenzoyI-D,L-(2-trifluoromethylphenyl)-
glycinyl]-4-(l-methylpiperidin-4-yl) piperazine (6.14. g, 11.8
mmol) was divided into 0.5 g lots and each lot was dissolved
in a mixture of isopropanol (2 0 mL) and heptane (30 mL).
These samples were then individually chromatographed using
preparative chiral HPLC (Chiralpak AD, 8 x 40 cm, eluting with
45% isopropanol/55% heptane with 0.2% DMEA for IS min at a
flow rate of 450 mL/min) . Analytical HPLC of the racernic
mixture (Chiralpak AD, 4.6 x 250 mm, eluting with 45%
isopropanol/55% heptane with 0.2% DMEA, 1.0 mL/min, UV
detection at 260 nm) revealed two peaks, baseline resolved.
The fractions from the preparative HPLC runs containing the
peak with the shorter retention time were combined and
concentrated in vacuo to give 2.9 g of isomer 1. The
fractions containing the later running isomer were combined
and concentrated to give 2.8 g of isomer 2 . Biological
evaluation of the two samples revealed isomer 1 to be over 100
times more potent than isomer 2; and, on that basis, isomer 1
was tentatively assigned as the D-isomer. Isomer 1 (2.7 g)
was then redissolved in dichloromethane and to this stirring
solution was added 1 M HC1 in diethyl ether (10.4 mL, 10.4
mmol) . The precipitate was filtered and dried in vacuo to
give 2.8 g (75%) of the title compound.
1H NMR
IS-MS, m/e 520.1 (M+l)
Analysis for C27H33N4O3F 2.1 HCl-1.4 H2O:
Calcd: C, .52.43; H, 6.14; N, 9.06; Cl, 12.04;
Found: C, 52.06; H, 6.03; N, 9.41; Cl.. 11.91.
Example 69
1-[Indole-6-carbonyl— D,L-(2-trif luoromethylphenyl) glycinyl] -
4-(l-methylpiperidin-4-yl)piperazine Hydrochloride.
Prepared from 1-[D,L-(2-trifluoromethylphenyl)glycinyl]-
4-(l-methylpiperidin-4-yl)piperazine and 6-carboxyindole using
procedures substantially equivalent to those described in
Method I-C followed by I-D.
1H NMR
IS-MS, m/e 528.0 (M+l)
Analysis for C28H32N5O2F3•1.9 HCl-2.5 H2O:
Calcd: C, 52.39; H, 6.10; N, 10.91; Cl, 10.50;
Found: C, 52.12; H, 5.61; N, 10.71; Cl, 10.63.
HPLC Analysis (Method A) : 97% tr = 21.10 min.
Example 70
1-[4-Methoxybenzoyl— D-cyclopentylglycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine Dihydrochloride.
Method I-G
To a stirring solution of HOBt (0.388 g, 2.87 mmol) in
DMF (2 mL) was added DCC (0.684 g, 2.65 mmol). To this
solution was added a solution of p-methoxybenzoic acid (0.404
g, 2.65 mmol) and 1-[D-cyclopentylglycinyl]-4-(1-
methylpiperidin-4-yl)piperazine (0.683 g, 2.21 mmol) in DMF (9
mL). After stirring overnight, the solution was filtered; and
the filtrate was loaded onto an SCX column (pretreated with 5%
acetic acid/methanol and washed with methanol). The column
was washed with methanol and then the product was eluted with
1 N ammonia/methanol followed by dichloromethane. The product
containing fractions were combined and concentrated in vacuo
to give 0.687 g, (70%, 1H NMR; IS-MS, m/e 443.4 (M+l)) of the
free base of the title compound.
The HC1 salt was prepared using Method I-D to give
73 7 mg (95%) of the title compound.
1H NMR
IS-MS, m/e 443 .4 (M+l)
Analysis for C25H38N4O3 2.1 HCl•2.0 H2O:
Calcd: C, 54.08; H, 8.01; N, 10.09; Cl, 13.41;
Found: C, 54.35; H, 7.76; N, 10.06; Cl, 13.64.
HPLC Analysis (Method A) : 99.4% tr = 17.84 min.
Example 71
1-[Indole-6-carbonyl— D-cyclopentylglycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine Dihydrochloride.
Prepared from indole-6-carboxylic acid and 1- [D-cyclo-
pentylglycinyl] -4-(l-methylpiperidin-4-yl)piperazine using
procedures substantially equivalent to those used in Method I-
G, using HOBt in place of HOAt and EDCI for DCC, and Method I-
D.
1H NMR
IS-MS, m/e 452.3 (M+l)
Analysis for C26H37N5O2 1.9 HCL 2.5 H20:
Calcd: C, 55.18; H, 7.82; N, 12.38; Cl, 11.90;
Found: C, 55.46; H, 7.47; N, 12.35; Cl, 11.79.
HPLC Analysis (Method A): 96.7% tr = 17.76 man.
Example 72
1- [4-Methoxybenzoyl- D-cyclohexylglycinyl] -4- (1-methyl-
piperidin-4-yl)piperazine Dihydrochloride.
Prepared from 4-methoxybenzoic acid and 1-[D-cyclohexyl-
glycinyl] -4- (l-methylpiperidin-4-yl)piperazine using
procedures substantially equivalent to those in Method I-G and
Method I-D.
1H NMR
IS-MS, m/e 457.4 (M+l)
Analysis for C26H40N4O3 HCl 0.6 H2O:
Calcd: C, 57.79; H, 8.06; N, 10.37; Cl, 13.12 ;
Found: C, 57.54; H, 8.02; N, 10.19; Cl, 13.22.
HPLC Analysis (Method A): 100% tr = 19.35 min.
Example 73
1- [Indole-6-carbonyl— D-cyclohexi'lglycinyl]-4-(l-methyl-
piperidin-4-yl)piperazine Dihydrochloride.
Prepared from indole-6-carboxylic acid and 1- [D-cyclo-
hexylglycinyl] -4- (l-methylpiperidin-4-yl)piperazine using
procedures substantially equivalent to those in Method I-G,
substituting HOAt for HOBt and EDCI for DCC, and Method I-D.
1H NMR
IS-MS, m/e 466.3 (M+l)
Analysis for C27H38N5O2 2.1 HC1-2.0 H20:
Calcd: C, 56.08; H, 7.86; N, 12.11; Cl, 12.88;
Found: C, 56.29; H, 7.47; N, 12.11; Cl, 12.76.
HPLC Analysis (Method A): 97.8% tr = 20.08 min.
Example 74a
1-[Indole-6-carbonyl— D-phenylglycinyl]-4-(2-phenethyl)-
piperazine.
Prepared from l-(D-phenylglycinyl)-4-(2-phenethyl) -
piperazine and indole-6-carboxylic acid using methods
substantially equivalent to those described in Method I-C
(62%) .
1H NMR (CDC13) .
APCI-MS, m/e = 467 (M+l).
Example 74b
1-[Indole-6-carbonyl- D-phenylglycinyl] -4-(2-phenethyl)-
piperazine Hydrochloride.
Prepared from 1- (indole-6-carbonyl-D-phenylglycinyl) -4-
(2-phenethyl)piperazine using methods substantially equivalent
to those described in Method I-D (96%).
[a]25D = -96.8 °C (c 0.25, methanol) .
Melting Point = 210-215 °C (dec.)
!h NMR (CD3OD).
HPLC Analysis (Method B) : 98. 6% tr = 16.5 min.
Analysis for C29H30N4O2 1.0 HCl 0.5 H2O:
Calcd: C, 68.02; H, 6.3 0; N, 10.94; Cl, 6.92
Found: C, 68.21; H, 6.32; N, 10.78; Cl, 6.78
APCI-MS, m/e =4 67 (M+l)
Example 75
1- [4-Methoxybenzoyl- D,L-thiazol-2-ylglycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine.
Prepared from 1-[D,L-(thiazol-2-yl)glycinyl]-4-(1-methyl-
piperidin-4-yDpiperazine trihydrochloride and anisoyl
chloride using method I-B, substituting N,N-di-
isopropylethylamine for potassium carbonate and substituting
dichloromethane for dioxane.
1H-NMR
LCMS m/z 458.4 (M+l)
Example 76a
1- [4-Methoxybenzoyl-D/L-(benzo [b] thiophen-3-yl) glycinyl]-4-
(l-methylpiperidin-4-yl)piperazine.
Prepared from 1-[D,L-(benzo [b]thiophen-3-yl)glycinyl]-4-
(l-methylpiperidin-4-yl)piperazine trihydrochloride and
anisoyl chloride using method G-A, substituting triethylamine
for potassium carbonate and substituting dichloromethane for.
dioxane.
1H-NMR
LCMS m/z 507.4 (M+l)
Example 76b
1-[4-Methoxybenzoyl- D,L-benzothiophene-3-ylglycinyl]-4-
(l-methylpiperidin-4-yl)piperazine Dihydrochloride.
Prepared from 1- [4-methoxybenzoyl-D,L- (benzo [b] thiophen-
3-yl) glycinyl]-4- (l-methylpiperidin-4-yl)piperazine and 0.2 N
HC1, followed by lyophilization.
LCMS m/z 507.4
Example 77a
1-[4-Methoxybenzoyl- D,L-naphthalene-l-ylglycinyl]-4-
(l-methylpiperidin-4-yl) piperazine.
Prepared from 1-[D,L-(naphthalen-1-yl)glycinyl]-4-
(l-methylpiperidin-4-yl)piperazine trihydrochloride and
anisoyl chloride using method G-A, substituting triethylamine
for potassium carbonate and substituting dichloromethane for
dioxane.
1H-NMR
IS-MS m/e 501.0 (M+l)
Example 77b
1-[4-Methoxybenzoyl— D,L-naphthalene-1-ylglycinyl]-4-
(1-methylpiperidin-4-yl) piperazine Dihydrochloride.
Prepared from 1-[D,L-(naphthalen-1-yl)glycinyl]-4-
(l-methylpiperidin-4-yl)piperazine and 0.2 N HC1, followed by
lyophilization.
1H-NMR
LCMS m/z 501.4 (M+l)
Example 78
1-[Indole-6-carbonyl— D,L-naphthalene-1-ylglycinyl]-4-
(l-methylpiperidin-4-yl)piperazine.
Prepared from 1-[D,L-(naphthalen-l-yl)glycinyl]-4-
(1-methylpiperidin-4-yl)piperazine trihydrochloride and
6-carboxyindole using method I-C, substitutuing EDCI for DCC
and substituting N,N-diisopropylamine for triethylamine.
IS-MS m/e 510.0 (M+l)
Example 79
1- [4-Methoxybenzoyl-D,L- (2-methylsulf onylphenyl) glycinyl] -4-
(1-methylpiperidin-4-yl)piperazine Hydrochloride.
Prepared from 1-[D,L-(2-methylsulfonylphenyl)glycinyl]-4-
(l-methylpiperidin-4-yl)piperazine and aniscyl chloride using
Method I-B, substituting triethylamine for potassium carbonate
and substituting dichloromethane for dioxane. The HCl salt
was prepared by Method I-D, substituting ethyl acetate for
dichloromethane.
1H-NMR
IS-MS, m/e 529 (M+l)
Example 80
1-[4-Methoxybenzoyl- D,L-(thiazol-5-yl)glycinyl]-4-
[2-(pyridin-4-yl) ethyl]piperazine Dihydrochloride.
To a stirred solution of 4-methoxybenzoic acid (760 mg,
5.0 mmol), 1-[D,L-(thiazol-5-yl) glycinyl]-4-[2-(pyridin-4-yl) -
ethyl]piperazine (circa 5.0 mmol) and HOAt (750 mg, 5.5 mmol)
in DMF (40 mL) was added EDCI (1.05 g, 5.5 mmol). The mixture
was stirred at room temperature for 20 h, and the solvent
removed in vacuo. The residues were taken up in chloroform:
isopropyl alcohol (2:1) and washed with satd sodium
bicarbonate. The aqueous phase was back extracted with
chloroform:isopropyl alcohol (2:1) (x3), and the combined
organic extracts were dried (MgS04) and concentrated in vacuo.
The crude product was purified by preparative RPHPLC; and the
product fractions concentrated, taken up in
chloroform:isopropyl alcohol (2:1), washed with satd sodium
bicarbonate, dried (MgSO4) and concentrated in vacuo. The
free base thus obtained was dissolved in methanol and treated
with 2 equivalents of HC1 in ether and evaporated to dryness.
The residue was dissolved in water/acetonitrile and freeze
dried to yield 786 mg of the.title compound.
LCMS M+l 466
NMR
Example 81
1- [4-Methoxybenzoyl- D,L- (2-methylthiazol-4-yl)glycinyl]-4-[2-
(pyridin-4-yl) ethyl]piperazine Dihydrochloride.
Prepared from 1- [D,L-(2-methylthiazol-4-yl)glycinyl]-4-
[2-(pyridin-4-yl) ethyl]piperazine and 4-methoxybenzoic acid
using methods substantially equivalent to those described in
Example 80.
LCMS M+l 480
NMR
Example 82
1- [4-Methoxybenzoyl- D,L-(2-aminothiazol-4-yl)glycinyl]-4-
[2-(pyridin-4-yl)ethyl]piperazine Dihydrochloride.
Prepared from 1- (Boc-D,L-2-aminothiazol-4-ylglycinyl)-4-[2-
(pyridin-4-yl)ethyl]piperazine and 4-methoxybenzoic acid using
methods substantially equivalent to those described in Example
80.
LCMS M+l 481
NNR
The following compounds are prepared using similar
procedures to those described above and the appropriate
starting materials:
1-[Indole-6-carbonyl— D-phenylglycinyl]-4-[2-(2-aminothiazol-
4-yl)ethyl]piperazine. (For example by coupling indole-
6-carboxylic acid with Intermediate A-10, followed by
deprotection of the amino group.)
1- [Indole-6-carbonyl-D-phenylglycinyl]-4-[2-(2-methylpyridin-
4-yl)ethyl]piperazine.
1- [Indole-6-carbonyl-D-phenylglycinyl] -4-[2-(2-trifluoro-
methylpyridin-6-yl)ethyl]piperazine.
1- [Indole-6-carbonyl-D- (2-chlorophenyl)glycinyl]-4-
[2-(pyridin-4-yl)ethyl]piperazine.
1- [Indole-6-carbonyl-D- (2-chlorophenyl) glycinyl]-4-
[2-(pyridazin-3-yl)ethyl]piperazine .
1- [Indole-6-carbonyl-D- (2 -chlorophenyl) glycinyl]-4-
[2-(imidazol-1-yl)ethyl]piperazine.
1-[Indole-6-carbonyl-D- (2-chlorophenyl)glycinyl]-4-
[2-(imidazol-4-yl)ethyl]piperazine.
1- [Indole-6-carbonyl-D- (2-chlorophenyl) glycinyl]-4-
[2-(pyrazol-4-yl)ethyl]piperazine.
1- [4-Methoxybenzoyl-D,L- (quinolin-8-yl)glycinyl]-4-(1-methyl-
piperidin-4-yl)piperazine.
Assay protocols
Enzyme Inhibition assays:
The ability of a test compound to inhibit factor Xa may be
evaluated in one or more of the following Enzyme Inhibition
assays, or in other standard assays known to those skilled in
the art.
Enzyme Inhibition Assay 1
Enzyme assays were carried out at room temperature in 0.1M
phosphate buffer, pH7.4 according to the method of Tapparelli
et al (J. Biol. Chem. 1993,268,4734-4741) . Purified human
factor Xa, trypsin, tnrombin and plasmin were purchased from
Alexis Corporation, Nottingham, UK. Urokinase was purchased
from Calbiochem, Nottingham, UK. Chromogenic substrates for
these enzymes; pefachrome-FXA, pefachrome-TRY, pefachrome-TH,
pefachrome-PL and pefachrome-UK were purchased from Pentapharm
AG, Basel, Switzerland. Product (p-nitroaniline) was
quantified by adsorption at 405nm in 96 well microplates using
a Dynatech MR5000 reader (Dynex Ltd, Billingshurst, UK). Km
and Ki were calculated using SAS PROC NLIN (SAS Institute,
Cary, NC, USA, Release 6.11) Km values were determined as
100.9µM for factor Xa/pefachrome-FXA and 81.6µM for
trypsin/pefachrome-TRY. Inhibitor stock solutions were
prepared at 40mM in Me2S0 and tested at 500µM, 50uM and 5µM.
Accuracy of Ki measurements was confirmed by comparison with
Ki values of known inhibitors of factor Xa and trypsin.
In agreement with published data, benzamidine inhibited factor
Xa, trypsin, thrombin, plasmin and urokinase with Ki values of
155µM, 2lµM, 330nM, 200nM and 100nM respectively. NAPAP
inhibited thrombin with a Ki value of 3nM. Compounds of the
invention were found to have activity in these assays.
Enzyme Inhibition Assay 2
Human factor Xa and human thrombin were purchased from Enzyme
Research Laboratories (South Bend, Indiana, USA). Other
proteases were from other commercial sources. Chromogenic
para-nitroanilide peptide protease substrates were purchased
from Midwest Biotech (Fishers, Indiana, USA).
The binding affinities for human factor Xa were measured as
apparent association constants (Kass) derived from protease
inhibition kinetics as described previously.a,b,c,d The
apparent Kass values were obtained using automated (BioMek-
1000) dilutions of inhibitors (Kass determinations are
performed in triplicate at each of four-eight inhibitor
concentrations) into 96-well plates and chromogenic substrate
hydrolysis rates determined at 405 nm using a Thermomax plate
reader from Molecular Devices (San Francisco). For factor Xa
inhibition, the assay protocol was: 50 µl buffer (0.06 M tris,
0.3 M NaCl, pH 7.4); 25 µl inhibitor test solution (in MeOH);
25 µl human factor Xa (32 nM in 0.03 M tris, 0.15 M NaCl, 1
mg/ml HSA) ; finally, 150 µl BzIleGluGlyArgpNA (0.3 mM in water)
added within 2 min to start hydrolysis. Final factor Xa was
3.2 nM. Free [Xa] and bound [Xa] were determined from linear
standard curves on the same plate by use of SoftmaxPro
software for each inhibitor concentration and apparent Kass
calculated for each inhibitor concentration which produced
hydrolysis inhibition between 20% and 80% of the control (3.2
nM factor Xa) : apparent Kass = [E:I]/[Ef] [If] =
[Eb] / [Ef] [Io-Ib] . The apparent Kass values so obtained are
approximately the inverse of the Ki for the respective
inhibitors [1/appKass = app Ki] . The variability of mean
apparent Kass values determined at the single substrate -
concentration was +/- 15%. The assay system Km was measured
as 0.347 +/- 0.031 mM [n=4] ; and Vmax was 13.11 +/- 0.76
uM/min.
Kass values were determined with thrombin and other proteases
using the same protocol with the following enzyme and
substrate concentrations: thrombin 5.9 nM with 0.2 mM
BzPheValArgpNA; XIa 1.2 nM with 0.4 mM pyroGluProArgpNA; Xlla
10 nM with 0.2 mM HDPr oPheArgpNA; plasmin 3 . 4 nM with 0.5 mM
HDValLeuLyspNA; nt-PA 1.2 nM with 0.8 mM HDIleProArgpNA; and
urokinase 0.4 nM with 0.4 mM pyroGluGlyArgpNA; aPC 3 nM with
0.174 mM pyroGluProArgpNA; plasma kallikrein 1. S nM with D-
ProPheArgpNA; bovine trypsin 1.4 nM with 0.18 mM
BzPheValArgpNA.
Citations
(a) Sail DJ, JA Bastian, SL Briggs, JA Buben, NY
Chirgadze, DK Clawson, ML Denny, DD Giera, DS Gifford-
Moore, RW Harper, KL Hauser, VJ Klimkowski, TJ Kohn, H-S
Lin, JR McCowan, AD Palkowitz, GF Smith, ME Richett, K
Takeuchi, KJ Thrasher, JM Tinsley, BG Utterback, S-CB
Yan, M Zhang. Dibasic Benzo[b]thiophenes Derivatives as
a Novel Class of Active Site Directed Thrombin
Inhibitors. 1. Determination of the Serine Protease
Selectivity, Structure-Activity Relationships and Binding
Orientation. J Med Chem 40 3489-3493 (1997) .
(b) Smith GF, TJ Craft, DS Gifford-Moore, WJ Coffman, KD Kurz,
E Roberts, RT Shuman, GE Sandusky, ND Jones, N Chirgadze, and
CV Jackson. A Family of Arginal Thrombin Inhibitors Related
to Efegatran. Sem. Thrombos. Hemost. 22, 173-183 (1996).
(c) Smith GF, DS Gif ford-Moore, TJ Craft, N Chirgadze, KJ
Ruterbories, TD Lindstrom, JH Satterwhite. Efegatran: A New
Cardiovascular Anticoagulant. In New Anticoagulants for the
Cardiovascular Patient. Ed. R Pifarre. Hanley & Belfus, Inc.,
Philadelphia (1997) pp 265-30.0.
(d) Sail DJ, JA Bastian, NY Chirgadze, ML Denny, MJ
Fisher, DS Gif ford-Moore, RW Harper, VJ Klimkowski, TJ
Kohn, HS Lin, JR McCowan, ME Richett, GF Smith, K.
Takeuchi, JE Toth, M Zhang. Diamino Benzo[b]thiophene
Derivatives as a Novel Class of Active Site Directed
Thrombin Inhibitors: 5. Potency, Efficacy and
Pharmacokmetic Properties of Modified C-3 Side Chain
Derivatives. In press, J Med Chem (1999) .
In general, the compounds of formula (I) exemplified herein
have been found to exhibit a Ki of 10 µM or less in Assay 1
and/or a Kass of at least 0.1 x 106 L/mole in Assay 2.
The ability of a test compound to elongate Partial
Thromboplastin Time (Prothrombin Time) may be evaluated in the
following test protocols.
Partial Thromboplastin Time (Prochrombin) Test Protocol
Venous blood was collected into 3.2% (0.109m) trisodium
citrate vacutainer tubes at 1 volume of anticoagulant to nine
volumes of blood. The blood cells were separated by
centrifugation at 700g for ten minutes to yield plasma, which
was frozen at 70°C until required.
To perform the test, l00µl of plasma was pipetted into in a
glass test tube, 1µl of test compound in DMSO was added, and
allowed to warm to 37° over two minutes. l00µl of warm (37°)
Manchester (tissue thromboplasin) reagent (Helena Biosciences,
UK) was added, allowed to equilibrate for two minutes. lOOul
of warm (37°) 25mM calcium chloride solution was added to
initiate clotting. The test tube was tilted three times
through a 90° angle every five seconds to mix the reagents and
the time to clot formation recorded. Data from a series of
observations and test compound concentrations are analysed by
a SAS statistical analysis' program and a CT2 (Concentration
required to double clotting time) for each compound is
generated.
Compounds of the invention were found to significantly
elongate the partial thromboplastin time (Prothrombin time).
Alternative Prothrombin Time and APTT Protocols
Coagulation Determinations. Prothrombin Times and APTT values
were determined in HUMAN PLASMA with a STA instrument (Stago) .
BioPT is a special non-plasma clotting assay triggered with
human tissue factor (Innovin). Possible binding to albumen or
to lipid was assessed by comparing the BioPT effects in the
presence/absence of 3 0 mg/ml human albumen (HSA) and 1 mg/ml
phosphatidyl choline (PC) . Inhibitors were delivered in 50%
MeOH vehicle.
APTT ASSAY
75 µl plasma Citrol Baxter-Dade Citrated Normal
Human Plasma
25 µl test sol'n
75 µl Actin Baxter-Dade Activated Cephaloplastin incubate 2 min
min. @ 3 7°
75 µl CaCl2 (0.C2 M)
PT ASSAY
75 µl plasma
25 µl test sol n
75 µl saline_____________incubate 1 min. @ 37° C
75 µl Innovin Baxter-Dade Recombinant Human Tissue Factor
Compounds of the invention were found to be potent inhibitors
of factor Xa.
We claim:
1 A substituted piperazine compound of formula (I)

wherein:
R2 represents:
(i) phenyl optionally being substituted in the 3 and/or
4 position by halo, nitro, thiol, haloalkoxy, hydrazido,
alkylhydrazido, amino, cyano, haloalkyl, alkylthio, alkenyl,
alkynyl, acylamino. tri or difluoromethoxy, carboxy, acyloxy,
MeSO2~ or R1, and optionally substituted at the 6 position by
aou.no, bydbcaaty, halo, alkyl, carboxy. alkxwycsudbonyl, cyano,
amido, aminoalkyl. alkoxy or alkylthio;
(ii) naphth-2-yl optionally substituted at the 6 or 7
position by halo, haloalkoxy, haloalkyl,, cyano. nitro,, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1j and optionally
substituted at the 3 position by amino, hydroxy, halo, alkyl,
carboxy, cyano, amido, aminoalkyl, alkoxy or alkylthio;
(iii) isoquinolin-7-yl, indol-5-yl, indol-6-yl, indazol-
5-yl, indazol-6-yl, benzothiazol-6-yl or benzisoxazol-5-yl
optionally substituted at the 3 position by halo, haloalkoxy,
haloalkyl, cyano, nitro, amino, hydrazido, alkylthio, alkenyl,
alkynyl or R1j;
(iv) benzimidazoi-5-yl or benzothiazol-6-yl optionally
substituted at the 2 position by amino;
(v) thien-2-yl or thien-3-yl optionally substituted at
t he 4 or 5 position by halo, haloalkoxy, haloalkyl, cyano,
nitro, amino, hydrazido, alkylthio, alkenyl, alkynyl or R2;
(vi) 3, 4-methylenedioxyphenyl, 2, 3-dihydroindol-6 -yl,
3 ,3-dichloro-2-oxo-indol-6-yl or 1-methyl- 3 - aminoindazol- 5 -yl:
(vii) benzothiazol -2 -yl, imidazo [1, 2 -a 1 pyrimidin-2 -yl or
t etrahydroimidazo [1, 2 -a] pvrimidin -2 -vl :
(viii) pyrazol-2-yl optionally substituted at the 5
position by halo, haloalkoxy, haloalkyl, cyano, nitro, ammo,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(ix) pyrid-2-yl optionally substituted at the 5 position
by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(x) pyrid-3-yl optionally substituted at the 6 position
by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1;
(xi) benzofur-2-yl optionally substituted at the 3
position by amino, hydroxy, halo, alkyl, carboxy, cyano,
amido, aminoalkyl, alkoxy or alkylthio and at the 5 or 6
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino,
hydrazido, alkylthio, alkenyl, alkynyl or R1j;
(xii) indol-2-yl optionally substituted on the indole
nitrogen atom by alkyl and optionally substituted at the 5 or
S position by halo, haloalfcoacy, haloalkyl, cyano, nitro,
amino, hydrazido, alkylthio, alkenyl, alkynyl or R1j;
(xiii) indol-6-yl substituted at the 5 position by amino,
hydroxy, halo, alkyl, carboxy, alkoxycarbonyl, cyano, amido,
aminoalkyl, alkoxy or alkylthio and optionally substituted at
the 3 position by halo, haloalkoxy, haloalkyl, cyano, nitro,
amino, hydrazido, alkylthio, alkenyl, alkynyl or R1j; or
(xiv) benzo[b]thiophen-2-yl optionally substituted at the
3 position by amino, hydroxy, halo, alkyl, carboxy, cyano,
amido, aminoalkyl, alkoxy or alkylthio and at the 5 or 6
position by halo, haloalkoxy, haloalkyl, cyano, nitro, amino
hydrazido, alkylthio, alkenyl, alkynyl or R1j; with the
proviso that R2 cannot be aminoisoqumolyl ;
R1 represents hydrogen, hydroxy, alkoxy, alkyl,
alkylaminoalkyl, alkanoyl, hydroxyalkyl, alkoxyailkyl,
alkoxycarbonyl, alkylaminocarbonyl, alkylamino, carboxyl,
carboxymethyl, amido or amidomethyl;
R1j represents hydrogen, hydroxy, alkoxy, alkyl,
alkanoyl, hydroxyalkyl, alkoxyalkyl, alkoxycarbonyl,
alkylamino, carboxyl, carboxymethyl, amido or amidomethyl;
-X-X- is -CONH-;
Y (the a-atom) is CH;
Cy represents an optionally R3a substituted: phenyl,
pyridyl, thienyl, thiazolyl, naphthyl, piperidinyl, furanyl,
pyrrolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxazolyl,
imidazolyl, 1,2,4 -thiadiazolyl, 1,3,4 -thiadiazoiyl,
pyrimidinyl, pyridazinyl, quinolyl, isoquinolyl, benzofuryl,
benzothienyl or cycloalkyl group, or a phenyl group
substituted by R3iXi in which Xi is a bond, O, NH or CH2 and
R3i is phenyl, pyridyl or pyrimidyl group optionally
substituted by R3a;
each R3a independently represents hydrogen,: hydroxyl;
alkoxy; aralkyloxy; alkyl; alkylaminoalkyl; hydroxymethyl;
carboxy; alkoxyalkyl; alkoxycarbonyl; alkylaminocarbonyl;
aminomethyl; CONH2; CH2CONH2; (1-6C)alkanoylamino;
alkoxycarbonylamino; amino; halo; cyano; nitro; thiol;
alkylthio; alkylsulphonyl; alkylsulphenyl; alkylsulphonamidd;
alkylaminosulphonyl; aisinosulpnonyl; haloalkoxy; haloalkyl; a
group of the fonmla -C(X3)W(R11)R12 (wherein X3 is O or S and
R11 and R12 are independently selected from hydrogen, methyl,
ethyl, or together with the nitrogen, atom to which they are
attached forat a pyrrol idin-l-yl, piperidin-1-yl or norpbolino
group; or
-OCH2O- which is bonded to two adjacent ring atoms in Cy; and
-L-Lp(D)n is of the formula:
in which Rr is -(CH2)C-RC- -CHReRf, -CH2-CHReRf,
-CH2-CH2-CHReRf, or Rg in which c is 1 or 2; Rc is thienyl,
thiazolyl(which may bear an amino substituent), isothiazolyl,
oxazolyl, isoxazolyl, pyrazolyl, imidazolyl, pyridyl (which
may bear an alkylsulphonyl, aminosulphonyl,
alkylaminosulphonyl, alkylaminocarbonyl, amino, amido, (1-
4C) alkoxycarbonyl, carboxy, acetylamino, chlorc, fluoro,
cyano, (l-3C)alkyl, trifluoromethyl, methoxy, ethoxy, nitre,
hydroxy, alkylsulphonylamino, triazolyl or tetrazoiyl
substituent) , pyrimidinyl, pyridazinyl, pyrazmyl or phenyl
(which may bear a methyl, methylamino, dimethyl amino, carbcxy.
dialkylaminosulphonyl, alkylsulphonyl , atninosulphonyl ,
alkylaminosulphonyl , alkylammocarbonyl, amino, amido,
alkoxycarbonyl, acetylamino, chloro, fluoro, cyano, methoxy,
ethoxy, nitro, hydroxy, alkylsulphonylarnino, triazolyl or
tetrazolyl substituent); each of Re and Rf independently is
hydrogen or C1-3alkyl; or CHReRf is cyclopentyl (which may
bear a hydroxy, amino, (1-3C) alkoxy, (1-3C) hydroxyalkyl, (1-
3C)alkyl, carboxy, methoxycarbonyl or ethoxycarbonyl
substituent at the 3- or 4-position), cyclohexyl (which may
bear a hydroxy, amino, (1-3C)alkoxy, (1-3C)hydroxyalkyl, (1-
3C)alkyl, carboxy, methoxycarbonyl or ethoxycarbonyl
substituent at the 3- or 4-position) , tetrahydropyran-4-yl,
tetrahydrothiopyran-4-yl, pyrrolidin-3-yl (which may bear a
hydroxy, amino, (1-3C)alkoxy, (1-3C)hydroxyalkyl, (l-3C)alkyl/
carboxy, methoxycarbonyl or ethoxycarbonyl substituent at the
1-position) . piperidin—4-yl (which may bear a hydroxy. amino,
(l-3Oalkoxy, (1-3c)hydroxyalkyl, (1-3C)alkyl, carboxy,
methoxycarbonyl or ethoxycarbonyl stibstituent at: the 1-
position), or indan-2-yl; and Rg is 2-methylsulphonylphenyl
which way bear a 4-fluoro substituent: oar Rg is ?6-1,1-
dianobenzo [b]thiopben-7-yl;
or a physiologically-tolerable salt: thereof;
provided that Lp(D)n is not of the formula (K):

wherein X2 is fluoro or hydrogen.
2. A compound according to Claim 1, wherein:
Cy is an optionally R3a substituted: phenyi, pyridyl,
Ithienyl, thiazolyl, naphthyl, piperidinyl or cycloalkyl group.
each R3a is independently selected from hydrogen,
nydroxyl, methoxy, ethoxy, methyl, ethyl, methylaminomethyl;
dimethylaminomethyl, hydroxymethyl, carboxy, methoxymetnvl,
methoxycarbonyl, ethoxycarbonyl, methylaminocarbonyl,
dimethylamino-carbonyl, aminomethyl, CONH2, CH2CONH2 ,
acetylamino, methoxycarbonylamino, ethoxycarbonylamino, t-
butoxycarbonylamino, amino, fluoro, chloro, cyano, nitro,
thiol, methylthio, methylsulphonyl, ethylsulphonyl,
methylsulphenyl, methylsulphonylamido, ethylsulphonylamido,
methylaminosulphonyl, ethylaminosulphonyl, aminosulphonyl,
trifluoromethoxy and trifluoromethyl; and
-L-Lp(D)n is of the formula:

in which Rr is -(CH2)C-RC, -CHReRf, -CH2-CHReRf, or Rg in
which c is 1 or 2; Rc is pyridyl or phenyl (which phenyl may
bear a fluoro, chloro, methyl, CONH2, SO2NH2,
methylaminosulphonyl, dimethylaminosulphonyl, methoxy or
methylsulphonyl substituent); each of Re and Rf independently
is hydrogen or C1-3alkyl; or CHReRf is cyclopentyl (which may
bear a methyl, ethyl or hydroxymethyl substituent at the 3- or
4-position), cyclohexyl (which may bear a methyl, ethyl or
hydroxymethyl substituent at the 3- or 4-position),
tetrahydropyran-4-yl, tetrahydrothiopyran-4-y1, pyrrolidin-3-
yl (which may bear a 1-methyl substituent), piperidin-4-yl
(which may bear a 1-methyl substituent) or Lndan-2-yl; and Rq
is 2-methylsulphonylphenyl which may bear a 4-fluoro
substituent or Rg is ?6-1, 1-dioxobenzo [b ] thiophen-7-yl.
3. A compound according to Claim 1 or claim 2, wherein R2
represents:
(i) phenyl optionally being substituted in the 3 and/or
4 position by fluoro, chloro, bromo, iodo, nitro,
difluoromethoxy, trifluoromethoxy, amino, cyano,
trifluoromethyl, methylthio, vinyl, carboxy, acetoxy, MeSO2-,
hydroxy, methoxy, ethoxy, methyl, methoxycarbonyl,
methylamino, ethylamino or amido, and optionally substituted
at the 6 position by amino, hydroxy, fluoro, methoxycarbonyl,
cyano or aminomethyl (preferably phenyl substituted in the 4
position by chloro, amino, vinyl, methylamino, methyl or
methoxy, optionally at the 3 position with amino or hydroxy,
and optionally at the 6 position with amino or hydroxy);
(ii) naphth-2-yl optionally substituted at the 6,
position by hydroxy and optionally substituted at the 3
position by amino or hydroxy;
(iii) isoquinolin-7-yl, indol-5-yl, indol-6-yl, indazol-
5-yl, indazol-6-yl, benzothiazol-6-yl or nenzisoxazol-5-yl
optionally substituted at the 3 position by chlorc, bromo,
amino, methyl or methoxy (preferably indol-6-yl optionally
substituted at the 3 position by chloro, bromo, methyl or
methoxy) ;
(iv) benzimi dazoi-5-yl or benzothiazol-6-yl optionally
substituted at the 2 position by amino;
(v) thien-2-yl or thien-3-yl optionally substituted at
the 4 or 5 position by methylthio, methyl or acetyl;
(vi) 3,4-methylenedioxyphenyl, 2,3-dihydroindol-6-yl,
) 3,3-dichloro-2-oxo-indol-6-yl or l-methyl~3-aminoindazol-5-yl;
(vii) benzothiazol-2-yl, imidazo[1,2-a]pyrimidin-2-yl or
tetrahydroimidazo[1,2-a]pyrimidin-2-yl ;
(viii) pyrazol-2-yl substituted at the b position by
methyl;
(ix) 5-chloropyrid-2-yl;
(x) pyrid-3-yl or 6-chloropyrid-3-y1;
(xi) benzofur-2-yl, 5-chLorobenzofur-2-yl,
3-methylbenzofur-2-yl, 5-methylbunzofur-2-yl or
6-methoxybenzofur-2-yl;
(xii) indol-2-yl optionally substituted on the indole
nitrogen atom by methyl and optionally substituted at the 5 or
6 position by fluoro, chloro, bromo, methyl or methoxy;
(xiii) indol-6-yl substituted at the 5 position by
chloro, fluoro or hydroxy and optionally substituted at the 3
position by chloro or methyl; or
(xiv) benzo[b]thiophen-2-yl optionally substituted at the
3 position by fluoro, chloro or methyl, and optionally
substituted at the 5 or 6 position by fluoro, chloro, methyl,
hydroxy, or methoxy.
4. A compound according to Claim 3, wherein R2 is:
(i) phenyl, 2-aminophenyl, 3-aminophenyl, 2-amino-4-
fluorophenyl, 2-amino-4-chlorophenyl, 2-amino-4-nitrophenyl,
2-amino-4-methylphenyl, 3,4-diaminophenyl, 3-amino-4-
fluorophenyl, 3-amino-4-chlorophenyl, 3-amino-4-bromophenyl,
3-amino-4-hydroxyphenyl, 3-amino-4-carboxyntethylphenyl, 3-
amino-4-methylphenyl, 3-amino-4-methoxyphenyl, 2-fluorophenyl,
4-fluoro-3-cyanophenyl, 3-chlorophenyl, 3-chloro-4-
hydroxyphenyl, 4-chlorophenyl, 4-chloro-2-hydroxyphenyl, 4-
chloro-3-hydroxyphenyl, 4-chloro-3-methylphenyl, 4-chloro-3-
methoxyphenyl, 4-bromophenyl, 4-bromo-3-methylphenyl, 4-
iodophenyl, 2-cyanophenyl, 3-cyanophenyl, 4-cyanophenyl, 2-
hydroxyphenyl, 2-hydroxy-4-methoxyphenyl, 3-hydroxyphenyl, 3-
hydroxy-4-methylphenyl, 2,4-dihydroxyphenyl, 3,4-
dihydroxyphenyl, 3-hydroxy-4-methoxyphenyl, 4-
difluoromethoxyphenyl, 4-trifluoromethoxyphenyl, 4-
trifluoromethylphenyl, 4-methylthiophenyl, 4-
methoxycarbonylphenyl, 4-acetoxyphenyl, 4-
methanesulfonylphenyl, 3-methylphenyl, 4-methylphenyl, 4-
vinylphenyl, 4-methoxyphenyl, 4-ethoxyphenyl, 4-methoxy-3-
chlorophenyl, 4-methoxy-3-methylphenyl, 3-methylaminophenyl,
4-methylaminophenyl, 4-ethylaminrphenyl or 2-
aminomethylphenyl;
(ii) naphth-2-yl, 3-aminonaphth-2-yl,, 3-hydroxynaphth-2-
yl or 6-hydroxynaphth-2-yl;
(iii) isoquinolin-7-yl, indol-5-y.l, indoL-6-yl, 3-
chloroindol-6-yl, 3-bromoindol-6-yl, 3-methylindol-6-yl, 3-
methoxyindol-6-yl, indazol-5-yl, 3-aminoindazol-5-yl, indazol-
6-yl, benzothiazol-6-yl, 3-aminobenzisoxazoL-5-yl;
(iv) benzimidazol-5-yl, 2-aminobenzimidazol-5-yl, or
benzothiazol-6-yl;
(v) thien-2-yl, 5-methylthien-2-yl, 5-methylthio-thien-2-
yl, 5-acetylthien-2-yl or thien-3-yl;
(vi) 3,4-methylenedioxyphenyl, 2,3-dihydroindol-6-yl,
3,3-dichloro-2-oxo-indol-6-yl or l-methyl~3-aminoindazol-5-yl;
(vii) benzothiazol-2-yl, imidazo[1,2-a]pyrimidin-2-yl or
tetrahydroimidazo[1,2-a]pyrimidin-2-yl;
(viii) 5-methylpyrazol-2-yl;
(ix) 5-chloropyrid-2-yl;
(x) pyrid-3-yl, 6-chloropyrid-3-yl;
(xi) benzofur-2-yl, 5-chlorobenzofur-2-yl, 3-
methylbenzofur-2-yl, 5-methylbenzofur-2-yl, 6-methoxybenzofur-
2-yl;r
(xii) indol-2-yl, 5-fluoroindol-2-yl, 5-chloroindol-2-yl,
5-methylindol-2-yl, 5-methoxindol-2-yl, 6-methoxyindol-2-yl
and l-methyl-indol-2-yl;
(xiii) 5-fluoroindol-6-yl; or
(xiv) benzo[b]thiophen-2-yl, 5-chloro- benzo[b]thiophen-
2-yl or 6-chlorobenzo[b]thiophen-2-yl.
5. A compound according to Claim 2 or Claim 3, wherein R2 is
selected from one of the formula (A') to (G'):
wherein R13 is selected from hydrogen,
fluoro [except for (C')], chloro or methyl and R14 is selected
from hydrogen, methyl, ethyl, fluoro, chloro, and methoxy and
R15 is selected from hydrogen, methyl, fluoro, chloro and
amino.
6. A compound according to claim 5, wherein R2 is 4-
chlorophenyl, 4-methoxyphenyl, 3-amino-4-chlorophenyl, indol-
2-yl, 5-chloroindol-2-yl, indol-6-yl, 3-chloroindol-6-yl or 3-
methylindol-6-yl.
7. A compound according to any one of claims 1 to 6, wherein
Cy is selected from:
wherein:
X' is selected from O, S and NMe;
X' is selected from O and S;
X'" is selected from O, S, NH and NMe;
Y' is selected from hydrogen, amino and methyl;
Ro is selected from hydrogen, methyl, fluoro, chloro,
trifluoromethyl, methoxy, methylthio, methylsulphinyl and
methylsulphonyl;
Rm is selected from hydrogen, methyl, fluoro, chloro,
trifluoromethyl, methoxy, methylthio, methylsulphinyl,
methylsulphonyl, carboxy, methoxycarbonyl and a group of the
formula -C(X3)N(R11)R12 (wherein X3 is 0 or S and P11 and R12
are independently selected from hydrogen, methyl or ethyl cr
together with the nitrogen atom to which they are attached
form a pyrrolidin-1-yl, piperidin-1-yl or morpholino group);
Rp is selected from hydrogen and fluoro; or
Ro and Rm or Rm and Rp form an -OCH2O- group; or
Ro and Rm together with the ring to which they are attached
form a 5 or 6 membered aryl or heteroaryl ring wherein the
heteroary ring contains 1 or 2 heteroatoms selected from
nitrogen, oxygen and sulfur);
one of Ro1 and RO2 is hydrogen and the other is Ro.
8. A compound according to any one of claims 1 to 7 wherein
Cy is selected from phenyl, 2-chlorophenyl, 2-methoxyphenyl,
4-carbamoylphenyl, pyrid-2-yl, pyrid-4-yl, thier.-2-yl, thien-
3-yl, furan-2-yl, furan-3-yl, imidazol-2-yl, thiazol-2-yl,
thiazol-4-yl, thiazol-5-yl and quinolin-4-yl.
9. A compound as claimed in any one of Claims 1 to 8,
wherein Rr is a -CHReRf, -CH2-CHReRf or -CH2-CH2-CHReRf group-
10 . A compound as claimed in claim 9, wherein -CHReRf is 2-
propyl, 3-pentyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl,
tetrahydrothio-pyran-4-yl, pyrrolidin-3-yl, 1-
methylpyrrolidin-3-yl, 1- (2-propyl)pyrrolidin-3-yl, piperidin-
4-yl, l-methylpiperidin-4-yl, 1-(2-propyl) piperidin-4-yl or
indan-2-yl.
11 . A compound as claimed in claim 10, wherein Rr is 1-
methylpiperidin-4-yl.
12 . A compound as claimed in any one of Claims 1 to 11, in
which the alpha atom in Y is carbon and has the conformation
that would result from construction from a D-a-aminoacid
NH2-CH(Cy)-C00H where the NH2 represents part of X-X.
13 . A compound as claimed in Claim 1, which is selected from:
1- (Indole-6-carbonyl-D-phenylglycinyl)-4-[2- (4-pyridinyl) -
ethyl] piperazine;
1- (3 -Chloroindole-6-carbonyl -D-phenylglycinyl) -
4- [2-(4-pyridinyl)ethyl]piperazine;
1- (4-Methoxybenzoyl-D-phenylglycinyl) -4- (1-methylpiperidin-4 -
yl) piperazine ,-
1- (Indole-6-carbonyl-D-phenylglycinyl) -4- (l-methylpiperidin-4 -
yl) piperazine ,-
1- (4-Methoxybenzoyl-D- (2-chlorophenyl)glycinyl) -4- (1-tnethyl-
piperidin-4 -yl) piperazine ;
1- (Indole-6-carbonyl-D- (2-chlorophenyl)glycinyl) -4- (l-methyl-
piperidin-4-yl) piperazine; and
1- (4-Methoxybenzoyl-D- (2-trif luoromethylphenyl) glycinyl) -4- (1-
methylpiperidin-4-yl) piperazine ,-
and physiologically-tolerable salts thereof.
14. A compound as claimed in Claim 13, which is l-(indole-6-
carbonyyl-D-phenylglycxyl)-4-(l-methflpiperidin-4-
yl)piperazine; osc a physiologically tolerable salt thereof.
15. A pharmaceutical composition, which comprises a compound
as claimed in any one of claim 1 to 14 together with at least
one pharmaceutically acceptable carrier or excipient,
16. A substituted piperazine compound of formula I as claimed in
claim 1 and named in any of the Examples herein, or a physiologically-
tolerable salt thereof.
17. A substituted piperazine compound of formula

Or a salt thereof, in which Cy is as defined in claim 1.
18. A substituted piperazine compound and a pharmaceutical composition,
substantially as hereinbefore described with reference to the foregoing examples.
Compounds of formula (I) in which R2, X, Y, Cy, L and Lp(D)n have the
meanings given in the specification, are inhibitors of the serine protease, Factor
Xa and pharmaceutical composition thereof are useful in the treatment of
cardiovascular disorders.

Documents:


Patent Number 225469
Indian Patent Application Number IN/PCT/2002/01273/KOL
PG Journal Number 46/2008
Publication Date 14-Nov-2008
Grant Date 12-Nov-2008
Date of Filing 09-Oct-2002
Name of Patentee ELI LILLY AND COMPANY
Applicant Address LILLY CORPORATE CENTER, INDIANAPOLIS, IN 46285
Inventors:
# Inventor's Name Inventor's Address
1 MAYER, MICHAEL, JOHN 116 ESSEX CIRCLE APARTMENT E, GULDERLAND, NY 12084
2 LIEBESCHUETZ, JOHN, WALTER LABURNUM COTTAGE, 42 BOLLINGTON ROAD, BOLLINGTON, MACCLESFIELD, CHESHIRE SK10 5EJ
3 MURRAY, CHRISTOPHER, WILLIAM 82 MOAT WAY, SWAVESEY, CAMBRIDGE CB4 5TR
4 YOUNG, STEPHEN, CLINTON 8 CRANBOURNE ROAD, HEATON MOOR, STOCKPORT SK4 4LD
5 CAMP, NICHOLAS, PAUL 10 COOKE RISE, WARFIELD, BRACKNELL BERKSHIRE RG42 2QN
6 JONES, STUART, DONALD 17 OSKWOOD DRIVE, PRESTBURY, MACCLESFIELD, CHESHIRE SK10 4HG
7 WYLIE, WILLIAM, ALEXANDER 68 DRUMHOY DRIVE, CARRICKFERGUS, COUNTY ANTRIM
8 MASTERS, JOHN, JOSEPH 12047 FLINT STONE COURT, FISHERS, IN 46038
9 WILEY, MICHAEL, ROBERT 7725 LANGWOOD DRIVE, INDIANAPOLIS, IN 46268
10 SHEEHAN, SCOTT, MARTIN 12485 WINDBUSH WAY, CARMEL, IN 46033
11 ENGEL, DAVID, BIRENBAUM 401 TULIP TREE, BLOOMINGTON, IN 47408
12 WATSON, BRIAN, MORGAN 3816 BRIAN PLACE, CARMEL, IN 46033
13 GUZZO, PETER, ROBERT 1146 MILLINGTON ROAD, NISKAYUNA, NY 12309
PCT International Classification Number C07D 295/18
PCT International Application Number PCT/GB2001/02553
PCT International Filing date 2001-06-12
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 PCT/GB2001/02553 2001-06-12 U.K.