Title of Invention

1-[ALKYL], 1-[HETEROARYL)ALKYL] AND 1-[ARYL)ALKYL]-7- (PYRIMIDIN-4-YL)-IMADAZO[1,2-a] PYRIMIDIN-5(1H)- ONE DERIVATIVES

Abstract The invention relates to a imidazo[1,2-a]pyrimidone derivative represented by formula (I) or a salt thereof: R1 wherein X represents a bond, an ethenylene group, an ethenylene group, a methylene group optionally substituted; a carbonyl group, an oxygen atom, a sulfur atom, a sulfonyl group, a sulfoxide group or a nitrogen atom being optionally substituted; R1 represents a 2, 4 or 5-pyrimidinyl optionally substituted; R2 represents a C1-6 alkyl group, a C1-2 perhalogenated alkyl group, a C1-3 halogenated alkyl group, a benzyl group, a benzene ring, a naphthalene ring, 5,6,7,8-tetrahydronaphthalene ring, a pyridine ring, an indole ring, a pyrrole ring, a thiophene ring, a furan ring or an imidazole ring, the benzyl group and the rings being optionally substituted; and n represents 0 to 3. The invention relates also to a medicament comprising the said derivative or a salt thereof as an active ingredient which is used for preventive and/or therapeutic treatment of a neurodegenerative disease caused by abnormal activity of GSK3ß, such as Alzheimer disease. (FIG. 1)
Full Text 1-[ALKYL], 1-[(HETEROARYL)ALKYL] AND 1-[(ARYL)ALKYL]-(PYRIMIDIN-
4-YL)-IMIDAZO[1,2-a]PYRIMIDIN-5(1 H)-ONE DERIVATIVES
SPECIFICATION
Technical Field
The present invention relates to compounds that are useful as an active
ingredient of a medicament for preventive and/or therapeutic treatment of
neurodegenerative diseases caused by abnormal activity of GSK3ß.
Background Art
GSK3ß (glycogen synthase kinase 3ß) is a proline directed serine,
threonine kinase that plays an important role in the control of metabolism,
differentiation and survival. It was initially identified as an enzyme able to
phosphorylate and hence inhibit glycogen synthase. It was later recognised that
GSK3P was identical to tau protein kinase 1 (TPK1), an enzyme that
phosphorylates tau protein in epitopes that are also found to be
hyperphosphorylated in Alzheimer"s disease and in several taupathies.
Interestingly, protein kinase B (AKT) phosphorylation of GSK3ß results in a loss of
its kinase activity, and it has been hypothesised that this inhibition may mediate
some of the effects of neurotrophic factors. Moreover, phosphorylation by GSK3ß
of ß-catenin, a protein involved in cell survival, results in its degradation by an
ubiquitinilation dependent proteasome pathway.
Thus, it appears that inhibition of GSK3ß activity may result in neurotrophic
activity. Indeed there is evidence that lithium, an uncompetitive inhibitor of GSK3ß,
enhances neuritogenesis in some models and also increases neuronal survival,
through the induction of survival factors such as Bcl-2 and the inhibition of the
expression of proapoptotic factors such as P53 and Bax.
Recent studies have demonstrated that ß-amyloid increases the GSK3ß activity
and tau protein phosphorylation. Moreover, this hyperphosphorylation as well as
the neurotoxic effects of ß-amyloid are blocked by lithium chloride and by a
GSK3ß antisense mRNA. These observations strongly suggest that GSK3ß may
be the link between the two major pathological processes in Alzheimer"s disease:
abnormal APP (Amyloid Precursor Protein) processing and tau protein
hyperphosphorylation.
Although tau hyperphosphorylation results in a destabilisation of the neuronal
cytoskeleton, the pathological consequences of abnormal GSK3ß activity are,
most likely, not only due to a pathological phosphorylation of tau protein because,
as mentioned above, an excessive activity of this kinase may affect survival
through the modulation of the expression of apoptotic and antiapoptotic factors.
Moreover, it has been shown that ß-amyloid-induced increase in GSK3ß activity
results in the phosphorylation and, hence the inhibition of pyruvate
dehydrogenase, a pivotal enzyme in energy production and acetylcholine
synthesis.
Altogether these experimental observations indicate that GSK3ß may find
application in the treatment of the neuropathological consequences and the
cognitive and attention deficits associated with Alzheimer"s disease, as well as
other acute and chronic neurodegenerative diseases. These include, in a non-
limiting manner, Parkinson"s disease, tauopathies (e.g. frontotemporoparietal
dementia, corticobasal degeneration, Pick"s disease, progressive supranuclear
palsy) and other dementia including vascular dementia; acute stroke and others
traumatic injuries; cerebrovascular accidents (e.g. age related macular
degeneration); brain and spinal cord trauma; peripheral neuropathies;
retinopathies and glaucoma.
In addition GSK3ß may find application in the treatment of other diseases such as:
Non-insulin dependent diabetes (such as diabetes type II ) and obesity; manic
depressive illness; schizophrenia; alopecia; cancers such as breast cancer, non-
small cell lung carcinoma, thyroid cancer, T or B-cell leukemia and several virus-
induced tumors.
Disclosure of the Invention
An object of the present invention is to provide compounds useful
as an active ingredient of a medicament for preventive and/or therapeutic
treatment of a disease caused by abnormal GSK3ß activity, more particularly of
neurodegenerative diseases. More specifically, the object is to provide novel
compounds useful as an active ingredient of a medicament that enables
prevention and/or treatment of neurodegenerative diseases such as Alzheimer"s
disease.
Thus, the inventors of the present invention have identified compounds
possessing inhibitory activity against GSK3ß. As a result, they found that
compounds represented by the following formula (I) had the desired activity and
were useful as an active ingredient of a medicament for preventive and/or
therapeutic treatment of the aforementioned diseases.
The present invention thus provides imidazo[1,2-a]pyrimidone derivatives
represented by formula (I) or salts thereof, solvates thereof or hydrates thereof:
wherein:
X represents a bond, an ethenylene group, an ethynytene group, a methylene
group optionally substituted by one or two groups selected from a C1-6 alkyl group,
a hydroxy group and a C1-4 alkoxy group;
a carbonyl group, an oxygen atom, a sulfur atom, a sulfonyl group, a sulfoxide
group or a nitrogen atom being optionally substituted by a C1-6 alkyl group;
R1 represents a 2, 4 or 5-pyrimidine ring optionally substituted by a C1-4 alkyl
group; C1-4 alkoxy group or a halogen atom;
R2 represents a C1-6 alkyl group, a C1-2 perhalogenated alkyl group, a C1-3
halogenated alkyl group, a benzyl group, a benzene ring, a naphthalene ring,
5,6,7,8-tetrahydronaphthalene ring, a pyridine ring, an indole ring, a pyrrole ring, a
thiophene ring, a furan ring or an imidazole ring, the benzyl group and the rings
being optionally substituted by 1 to 4 substituents selected from a C1-6 alkyl group,
a benzene ring, a halogen atom, a C1-2 perhalogenated alkyl group, a C1-3
halogenated alkyl group, a hydroxyl group, a C1-4 alkoxy group, a nitro, a cyano,
an amino, a C1-6 monoalkylamino group or a C2-10 dialkylamino group;
and n represents 0 to 3.
According to another aspect of the present invention, there is provided a
medicament comprising as an active ingredient a substance selected from the
group consisting of the pyrimidone derivatives represented by formula (I) and the
physiologically acceptable salts thereof, and the solvates thereof and the hydrates
thereof. As preferred embodiments of the medicament, there are provided the
aforementioned medicament which is used for preventive and/or therapeutic
treatment of diseases caused by abnormal GSK3b activity, and the
aforementioned medicament which is used for preventive and/or therapeutic
treatment of neurodegenerative diseases and in addition other diseases such as:
Non-insulin dependent diabetes (such as diabetes type II) and obesity; manic
depressive illness; schizophrenia; alopecia; cancers such as breast cancer, non-
small cell lung carcinoma, thyroid cancer, T or B-cell leukemia and several virus-
induced tumors.
As further preferred embodiments of the present invention, there are provided the
aforementioned medicament wherein the diseases are neurodegenerative
diseases and are selected from the group consisting of Alzheimer"s disease,
Parkinson"s disease, tauopathies (e.g. frontotemporoparietal dementia,
corticobasal degeneration, Pick"s disease, progressive supranuclear palsy) and
other dementia including vascular dementia; acute stroke and others traumatic
injuries; cerebrovascular accidents (e.g. age related macular degeneration); brain
and spinal cord trauma; peripheral neuropathies; retinopathies and glaucoma, and
the aforementioned medicament in the form of pharmaceutical composition
containing the above substance as an active ingredient together with one or more
pharmaceutical additives.
4
The present invention further pr6vides an inhibitor of GSK3ß activity
comprising as an active ingredient a substance selected from the group consisting
of the imidazo[1,2-a]pyrimidone derivatives of formula (I) and the salts thereof,
and the solvates thereof and the hydrates thereof.
According to further aspects of the present invention, there is provided a
method for preventive and/or therapeutic treatment of neurodegenerative
diseases caused by abnormal GSK3ß activity, which comprises the step of
administering to a patient a preventively and/or therapeutically effective amount of
a substance selected from the group consisting of the imidazo[1,2-a]pyrimidone
derivatives of formula (I) and the physiologically acceptable salts thereof, and the
solvates thereof and the hydrates thereof; and a use of a substance selected from
the group consisting of the imidazo[1,2-a]pyrimidone derivatives of formula (I) and
the physiologically acceptable salts thereof, and the solvates thereof and the
hydrates thereof for the manufacture of the aforementioned medicament.
As used herein, the C1-6 alkyl group represents a straight or branched
alkyl group having 1 to 6 carbon atoms, for example, methyl group, ethyl group, n-
propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-
butyl group, n-pentyl group, isopentyl group, neopentyl group, 1,1-dimethylpropyl
group, n-hexyl group, isohexyl group, and the like;
The C1-4 alkoxy group represents an alkyloxy group having 1 to 4 carbon
atoms for example, methoxy group, ethoxy group, propoxy group, isopropoxy
group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, and
the like;
The halogen atom represents a fluorine, chlorine, bromine or iodine atom;
The C1-2 perhalogenated alkyl group represents an alkyl group wherein all the
hydrogen have been substituted by a halogen atom, for example a CF3 or C2F5;
The C1-3 halogenated alkyl group represents an alkyl group wherein at
least one hydrogen has not been substituted by an halogen atom;
The C1-6 monoalkylamino group represents an amino group substituted by
one C1-6 alkyl group, for example, methylamino group, ethylamino group,
propylamino group, isopropylamino group, butylamino group, isobutylamino
group, tert-butylamino group, pentylamino group and isopentyiamino group;
The C2-10 dialkylamino group represents an amino group substituted by
two C1-5 alkyl groups, for example, dimethylamino group, ethylmethylamino group,
diethylamino group, methylpropylamino group and diisopropylamino group;
The methylene group represents a divalent group of formula: -CH2-
The ethenylene group represents the divalent group of formula:
The ethynylene group represents the divalent group of formula:
The leaving group represents a group which could be easily cleaved and
substituted, such a group may be for example a tosyloxy, a mesyloxy, a bromide
and the like.
The compounds represented by the aforementioned formula (I) may form
a salt. Examples of the salt include, when an acidic group exists, salts of alkali
metals and alkaline earth metals such as lithium, sodium, potassium, magnesium,
and calcium; salts of ammonia and amines such as methylamine, dimethylamine,
trimethylamine, dicyclohexylamine, tris(hydroxymethyl)arninomethane, N,N-
bis(hydroxyethyl)piperazine, 2-amino-2-methyl-1-propanol, ethanolamine, N-
methylglucamine, and L-glucamine; or salts with basic amino acids such as lysine,
6-hydroxylysine, and arginine. The base-addition salts of acidic compounds are
prepared by standard procedures well known in the art.
When a basic group exists, examples include salts with mineral acids
such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric
acid; salts with organic acids such as methanesulfonic acid, benzenesulfonic acid,
p-tofuenesulfonic acid, acetic add, propionic acid, tartaric acid, fumaric acid,
maleic acid, malic acid, oxalic acid, succinic acid, citric acid, benzoic acid,
mandelic acid, cinnamic acid, lactic acid, glycolic acid, glucuronic acid, ascorbic
acid, nicotinic acid, and salicylic acid; or safts with acidic amino acids such as
aspartic acid, and glutamic acid.
The acid-addition salts of the basic compounds are prepared by standard
procedures well know in the art which include, but are not fi"mited thereto,
dissolving the free base in an aqueous alcohol solution containing the appropriate
acid and isolating the salt by evaporating the solution, or by reacting the free base
and an add in an organic solvent, in which case the salt separates directly, or ts
precipitated with a second organic solvent, or can be obtained by concentration of
the solution. The acids which can be used to prepare the acid-addition salts
incfude preferably those which produce, when combined with the free base,
pharmaceutically-acceptable salts, that is, salts whose anions are relatively
innocuous to the animal organism in pharmaceutical doses of the salts, so that the
beneficial properties inherent in the free base are not compromised by side effects
ascribable to the anions. Although medicinally acceptable salts of the basic
compounds are preferred, all acid-addition salts are within the scope of the
present invention.
In addition to the imidazo[1,2-a]pyrimidone derivatives represented by the
aforementioned formula (I) and salts thereof, their solvates and hydrates also fall
within the scope of the present invention. The imidazo[1,2-a]pyrimidone
derivatives represented by the aforementioned formula (I) may have one or more
asymmetric carbon atoms. As for the stereochemistry of such asymmetric carbon
atoms, they may independently be in either (R) and (S) configuration, and the
imidazo[1,2-a]pyrimidone derivative may exist as stereoisomers such as optical
isomers, or diastereoisomers. Any stereoisomers in pure form, any mixtures of
stereoisomers, racemates and the like fall within the scope of the present
invention.
Examples of preferred compounds of the present invention are shown in
table 1 hereinafter. However, the scope of the present invention is not limited by
these compounds.
Preferred compounds of the present invention represented by formula (I)
include also:
(1) Compounds wherein R1 represents a 4 or 5-pyiimidine ring and more
preferably a 4-pyrimidtne ring, which may be substituted by a C1-2 alkyl group,
a C1-2 alkoxy group or a halogen atom; and/or
(2) X represents a bond, a methylene group optionally substituted or a carbonyl
group.
More preferred compounds of the present invention represented by formula (I)
include also:
(1) Compounds wherein R1 represents an unsubstituted 4-pyrimidine ring; and/or
(2) Compounds wherein R2 represents a benzene ring, a naphthalene ring or a
5,6,7,8-tetrahydronaphthalene ring; more preferably a benzene ring or a
naphthalene ring; the rings being optionally substituted; and/or
(3) Compounds wherein X represents an unsubstituted methylene group or a
carbony! group.
Particularly preferred compounds of the present invention represented by formula
(I) include:
1 1 -(3-Phenyl-propyl)-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-one
2 1-[3-(2-Fluoro-phenyl)-propyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
3 1-[2-(4-Fluoro-2-methoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
4 1-[2-(4-Methoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
5 1-[2-(4-Methyl-phenyl)-ethyll-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
6 1-(2-Naphthalen-1-yl-ethyl)-7-(pyrimidin-4-y|)-1H-imidazo[1,2-a]pyrimidin-
5-one
7 1-[2-(3-Fluoro-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
8 1 -[2-(3-Chloro-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
9 1-[2-(2-Methoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
10 4-[2-(5-Oxo-7-(pyrimidin-4-yl)-5H-imidazo[1,2-a]pyrimidin-1 -yl)-ethyl]-
benzonitrile
11 1-(2-Hydroxy-2-phenyl-ethyl)-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
12 1 -(2-Oxo-2-phenyl-ethyl)-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one
13 1 -[2-(4-Fluoro-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
14 1 -[2-(4-Ethoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
15 1 -[2-(2,5-Dimethoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one.
As a further object, the present invention concerns also methods for preparing the
imidazo[1,2-a}pyrimidone compounds represented by the aforementioned formula
(I).
These compounds can be prepared, for example, according to methods explained
below.
Preparation method
Imida2o[1,2-a]pyrimidone compounds represented by the aforementioned
formula (I) may be prepared according to scheme 1.
(In the above scheme the definition of R1, R2, X and n are the same as
those already described for compound of formula (1)).
The 7-(pyrimidinyl)-imidazo[1,2-a]pyrimidin-5(1H)-one derivative
represented by the above formula (III), wherein R1 is as defined for compound of .
formula (I), is allowed to react with a base such as sodium hydride, sodium
carbonate or potassium carbonate in a solvent such as N,N-dimethylforrnamide,
N-methylpyrrolidine, N,N-dimethylacetamide or chloroform at a suitable
temperature ranging from 0 to 130°C under ordinary air, then with a compound of
formula (II), wherein R2, X and n are as defined for compound of formula (I) and L
represents a leaving group preferably bromide or mesyloxy group, is added to
obtain the compound of the aforementioned formula (I).
Compound of formula (H) are commercially available or may be
synthesised according to well-known methods of one skilled in the art. The
compound of formula (III) may be prepared according to the method defined in
scheme 2.
(In the above scheme the definition of R1 is the same as already
described.)
According to this method, the 3-ketoester of formula (V), wherein R represents an
alkyl group such as for example a methyl or ethyl group, is allowed to react with a
2-aminoimidazole of formula (IV). The reaction may be carried out in the presence
of an ammonium salt such as ammonium acetate, in a alcoholic solvent such as
methanol, ethanol and the like or without, at a suitable temperature ranging from
25°-140°C under ordinary air.
Compound of formula (IV) is commercially available, compound of
formula (V) may be synthesised by analogy to the method described in patent
DE2705582.
For example compounds of formula (V), wherein R1 represent a pyrimidine ring.
optionally substituted by a C1-4 alkyl group, C1-4 alkoxy group or a halogen atom,
can be prepared by reacting a pyrimidinyl-4-carboxylic acid optionally substituted
by a C1-4 alkyl group, C1-4 alkoxy group or an halogen, with a malonic acid
monoester. The reaction can be carried out using methods we// known to one
skilled in the art, such as for example in presence of a coupling agent such as
1,1"-carbonylbis-1H-imidazole in a solvent such as tetrahydrofuran at a
temperature ranging from 20 to 70°C.
In the above reactions, protection or deprotection of a functional group
may sometimes be necessary. A suitab/e protecting group Pg can he chosen
depending on the type of the functional group, and a method described in the
literature may be applied. Examples of protecting groups, of protection and
deprotection methods are given for example in Protective groups in Organic
Synthesis Greene et a}., 2nd Ed. (John Wiley & Sons, Inc., New York).
The compounds of the present invention have inhibitory activity against GSK3ß.
Accordingly, the compounds of the present invention are useful as an active
ingredient for the preparation of a medicament, which enables preventive and/or
therapeutic treatment of a disease caused by abnormal GSK3ß activity and more
particularly of neurodegenerative diseases such as Alzheimer"s disease. In
addition, the compounds of the present invention are also useful as an active
ingredient for the preparation of a medicament for preventive and/or therapeutic
treatment of neurodegenerative diseases such as Parkinson"s disease,
tauopathtes (e.g. frontotemporoparietal dementia, corticobasal degeneration,
Pick"s disease, progressive supranuclear palsy) and other dementia including
vascular dementia; acute stroke and others traumatic injuries; cerebrovascular
accidents (e.g. age related macular degeneration); brain and spinal cord trauma;
peripheral neuropathies; retinopathies and glaucoma; and other diseases such as
non-insulin dependent diabetes (such as diabetes type II) and obesity; manic
depressive illness; schizophrenia; alopecia;-cancers such as breast cancer, non-
small cell lung carcinoma, thyroid cancer, T or B-cell leukemia and several virus-
induced tumors.
The present invention further relates to a method for treating
neurodegenerative diseases caused by abnormal activity of GSK3ß and of the
aforementioned diseases which comprises administering to a mammalian
organism in need thereof an effective amount of a compound of the formula (I).
As the active ingredient of the medicament of the present invention, a
substance may be used which is selected from the group consisting of the
compound represented by the aforementioned formula (I) and pharmacologically
acceptable salts thereof, and solvates thereof and hydrates thereof. The
substance, per se, may be administered as the medicament of the present
invention, however, it is desirable to administer the medicament in a form of a
pharmaceutical composition which comprises the aforementioned substance as
an active ingredient and one or more pharmaceutical additives. As the active
ingredient of the medicament of the present invention, two or more of the
aforementioned substances may be used in combination. The above
pharmaceutical composition may be supplemented with an active ingredient of
another medicament for the treatment of the above mentioned diseases. The type
of pharmaceutical composition is not particularly limited, and the composition may
be provided as any formulation for oral or parenteral administration. For example,
the pharmaceutical composition may be formulated, for example, in the form of
pharmaceutical compositions for oral administration such as granules, fine
granules, powders, hard capsules, soft capsules, syrups, emulsions, suspensions,
solutions and the like, or in the form of pharmaceutical compositions for parenteral
administrations such as injections for intravenous, intramuscular, or subcutaneous
administration, drip infusions, transdermal preparations, transmucosal
preparations, nasal drops, inhalants, suppositories and the like. Injections or drip
infusions may be prepared as powdery preparations such as in the form of
lyophilised preparations, and may be used by dissolving just before use in an
appropriate aqueous medium such as physiological saline. Sustained-release
preparations such as those coated with a polymer may be directly administered
intracerebrally.
Types of pharmaceutical additives used for the manufacture of the
pharmaceutical composition, content ratios of the pharmaceutical additives
relative to the active ingredient, and methods for preparing the pharmaceutical
composition may be appropriately chosen by those skilled in the art. Inorganic or
organic substances, or solid or liquid substances may be used as pharmaceutical
additives. Generally, the pharmaceutical additives may be incorporated in a ratio
ranging from 1% by weight to 90% by weight based on the weight of an active
ingredient.
Examples of excipients used for the preparation of solid pharmaceutical
compositions include, for example, lactose, sucrose, starch, talc, cellulose,
dextrin, kaolin, calcium carbonate and the like. For the preparation of liquid
compositions for oral administration, a conventional inert diluent such as water or
a vegetable oil may be used. The liquid composition may contain, in addition to
the inert diluent, auxiliaries such as moistening agents, suspension aids,
sweeteners, aromatics, colorants, and preservatives. The liquid composition may
be filled in capsules made of an absorbable material such as gelatin. Examples of
solvents or suspension mediums used for the preparation of compositions for
parenteral administration, e.g. injections, suppositories, include water, propylene
glycol, polyethylene glycol, benzyl alcohol, ethyl oleate, lecithin and the like.
Examples of base materials used for suppositories include, for example, cacao
butter, emulsified cacao butter, lauric lipid, witepsol.
The dose and frequency of administration of the medicament of the
present invention are not particularly limited, and they may be appropriately
chosen depending on conditions such as a purpose of preventive and/or
therapeutic treatment, a type of a disease, the body weight or age of a patient,
severity of a disease and the like. Generally, a daily dose for oral administration
to an adult may be 0.01 to 1,000 mg (the weight of an active ingredient), and the
dose may be administered once a day or several times a day as divided portions,
or once in several days. When the medicament is used as an injection,
administrations may preferably be performed continuously or intermittently in a
daily dose of 0.001 to 100 mg (the weight of an active ingredient) to an adult.
Chemical Examples
The present invention will be explained more specifically with reference to
the following general examples, however, the scope of the present invention is not
limited to these examples.
Example 1 (Compound ? 2 of table 1)
1 -[3-(2-Fluoro-phenyl)-propyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-one
hydrochloride (1:1)
1.1. 7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-one
A mixture containing 2.9g (15 mmol) of 3-oxo-3-(pyrimidin-4-yl)-propionic
acid ethyl ester (prepared by analogy to the method described in patent DE
2705582), 2g (15 mmol) of 2-aminoimidazole hemisulfate and 1.2g (15 mmol) of.
ammonium acetate was heated at 140°C during 18 h.
The cooled mixture was treated with 30ml of acetonitrile and filtered and the
precipitate was added to water and heated at reflux temperature for 30 min.
The resulting solution was cooled and the precipitate recovered by filtration. The
crude product thus obtained was recrystallised from ethanol to give 1.75g of pure
product as a gray solid.
Mp: 345-346°C
1.2. 1 -[3-(2-Fluoro-phenyl)-propyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one hydrochloride (1:1)
A suspension of 0.433g (2.03 mmol) of 7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one in 4ml of anhydrous N,N-dimethylformamide was treated with
365mg (2.64 mmol) of potassium carbonate and the resulting mixture was heated
at 70 °C for 30 min. 530mg (2.44 mmol) of 3-(2-fluoro-phenyl)propyl bromide was
added and the reaction mixture was heated at 130 °C during 1h.
The cooled solution was treated with water and extracted with ethyl acetate. The
organic phase was dried and evaporated to give crude product which was purified
by silica gel chromatography, eluting with dichloromethane/methanol in the
proportions 100/0 to 95/5. There is obtained 0.248g of pure product in the form of
the free base which was transformed into the hydrochloride salt.
Mp: 192-194°C.
Example 2 (Compound ?3 of table 1)
1 -[2-(4-Fluoro-2-methoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
2.1 (4-Fluoro-2-methoxy-phenyl)-acetic acid methyl ester
To a suspension of 14.34g (32.47 mmol) of lead (IV) acetate in 100ml of
anhydrous toluene was added a mixture of 5.2g (30.92 mmol) of 1-(4-fluoro-2-
methoxy-phenyl)-ethanone and 15.02 ml (123.13 mmol) of boron trifluoride
etherate in 9ml of methanol. The reaction mixture is further stirred at room
temperature for 16h. Water was added to the cooled mixture and the resulting
solution extracted with toluene. The extracts were washed with saturated sodium
hydrogen carbonate solution, saturated sodium chloride solution and dried with
sodium sulphate. The so/vent was evaporated to dryness to give 6g of product as
an oil which was used in the subsequent step without further purification.
2.2 2-(4-Fiuoro-2-methoxy-phenyl)-ethanol
To a suspension of 1.72g ( 45.41 mmol) of lithium aluminium hydride in 120ml of
tetrahydrofuran at 0°C was added dropwise 6g (30.27 mmol) of dissolved in 120
ml of (4-f!uoro-2-methoxy-pheny!)-acetic acid methyl ester and the resulting
mixture stirred at room temperature for 1 h.
The reaction mixture was diluted with 100ml of diethylether at 0°C and treated
with excess of a saturated aqueous solution of sodium sulphate. Further solid
sodium sulphate was added and the organic phase was filtered to remove salts.
The solvent was evaporated to dryness to give 5.1g (99%) of product as an oil.
2.3 Methanesulfonic acid 2-(4-fluoro-2-methoxy-phenyi)-ethyI ester
To a solution of 5.1g (29.97 mmol) of 2-(4-fluoro-2-methoxy-phenyl)-ethanol in 30
ml of anhydrous dichloromethane was added at 0°C 6.26ml (44.95 mmol) of
triethylamine and 3.5ml (44.95 mmol) of methanesulfonyl chloride.
The resulting mixture was stirred at 0°C for 1h. The mixture was then diluted
with water and dichloromethane and extracted with dichloromethane. Organic
layer was dried and evaporated to give 7g(100%) of methanesulfonic acid 2-(4-
fluoro-2-methoxy-phenyl)-ethyl ester.
2.4 1-[2-(4-Fluoro-2-methoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one
A suspension of 0.4g (1.88 mmol) of 7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one in 10ml of anhydrous N,N-dimethylformamide was treated with
337mg (2.44 mmol) of potassium carbonate and the resulting mixture was heated
at 70°C for 30 min. 605mg (2.44 mmol) of methanesulfonic acid 2-(4-fluoro-2-
methoxy-phenyl)-ethyl ester was added and the reaction mixture was heated at 80
°C during 16h.
The cooled solution was treated with water and extracted with ethyl acetate. The
organic phase was dried and evaporated to give crude product which was purified
by silica gel chromatography, eluting with dichloromethane/methanol in the
proportions 100/0 to 95/5. There is obtained 0.12g of pure product in the form of
the free base.
Mp: 196-198°C.
A list of chemical structures and physical data for compounds of the.
aforementioned formula (I) illustrating the present invention is given in table 1.
The compounds have been prepared according to the methods of the example.
In the table, R1 is an unsubstituted 4-pyrimidine ring Ph represents a phenyl
group, (S) indicates the stereochemistry of the carbon atom, and "__" in the
structure of R2 represents the bond attached to X.
Test Example: Inhibitory activity of the medicament of the present invention
against GSK3ß:
Two different protocols can be used.
In a first protocol : 7.5 µM of prephosphorylated GS1 peptide and 10 µM ATP
(containing 300,000 cpm of 33P-ATP) were incubated in 25 mM Tris-HCI, pH 7.5,
0.6 mM DTT, 6 mM MgCI2, 0.6 mM EGTA, 0.05 mg/ml BSA buffer for 1 hour at
room temperature in the presence of GSK3ß (total reaction volume : 100
microliters).
In a second protocol: 4.1 µM of prephosphorylated GS1 peptide and 42 µM ATP
(containing 260,000 cpm 33P-ATP) were incubated in 80 mM Mes-NaOH, pH 6.5,
1 mM Mg acetate, 0.5 mM EGTA, 5 mM 2-mercaptoethanol, 0.02% Tween 20,
10% glycerol buffer for 2 hours at room temperature in the presence of GSK3ß.
Inhibitors were solubilised in DMSO (final solvent concentration in the reaction
medium, 1%).
The reaction was stopped with 100 microliters of a solution made of 25 g
polyphosphoric acid (85% P2O5), 126 ml 85% H3PO4, H2O to 500 ml and then
diluted to 1:100 before use. An aliquot of the reaction mixture was then
transferred to Whatman P81 cation exchange filters and rinsed with the solution
described above. Incorporated 33P radioactivity was determined by liquid
scintillation spectrometry.
The phosphorylated GS-1 peptide had the following sequence :
NH2-YRRAAVPPSPSLSRHSSPHQS(P)EDEE-COOH.
The GSK3ß inhibitory activity of the compounds of the present invention are
expressed in IC50, and as an illustration the range of IC50"s of the compounds in
table 1 is between 20 nanomolar to 1 micromolar concentrations.
As for example compound No. 6 of table 1 shows an IC50 of 21 nM.
Formulation Example
(1) Tablets
The ingredients below were mixed by an ordinary method and
compressed by using a conventional apparatus.
Compound of Example 1 30 mg
Crystalline cellulose 60 mg
Corn starch 100mg
Lactose 200 mg
Magnesium stearate 4 mg
(2) Soft capsules
The ingredients below were mixed by an ordinary method and filled in soft
capsules.
Compound of Example 1 30 mg
Olive oil 300 mg
Lecithin 20 mg
(1) Parenteral preparations
The ingredients below were mixed by an ordinary method to prepare
injections contained in a 1 ml ampoule.
Compound of Example 1 3 mg
Sodium chloride 4 mg
Distilled water for injection 1 ml
Industrial Applicability
The compounds of the present invention have GSK3b inhibitory activity
and are useful as an active ingredient of a medicament for preventive and/or
therapeutic treatment of diseases caused by abnormal activity of GSK3ß and
more particularly of neurodegenerative diseases.
We claim :
1. An imidazo[1,2-a]pyrimidone derivative represented by formula (I) or a
salt thereof, or a solvate thereof or a hydrate thereof:
wherein:
X represents a bond, an ethenylene group, an ethynylene group, a methylene
group optionally substituted by one or two groups selected from a C1-6 alkyl group,
a hydroxy group and a C1-4 alkoxy group;
a carbonyl group, an oxygen atom, a sulfur atom, a sulfonyl group, a sulfoxide
group or a nitrogen atom being optionally substituted by a C1-6 alkyl group;
R1 represents a 2, 4 or 5-pyrimidinyl optionally substituted by a C1-4 alkyl group,
C1-4 alkoxy group or a halogen atom;
R2 represents a C1-6 alkyl group, a C1-2 perhalogenated alkyl group, a C1-3
halogenated alkyl group, a benzyl group, a benzene ring, a naphthalene ring,
5,6,7,8-tetrahydronaphthalene ring, a pyridine ring, an indole ring, a pyrrole ring, a
thiophene ring, a furan ring or an imidazole ring, the benzyl group and the rings
being optionally substituted by 1 to 4 substituents selected from a C1-6 alkyl group,.
a benzene ring, a halogen atom, a C1-2 perhalogenated alkyl group, a C1-3
halogenated alkyl group, a hydroxyl group, a C1-4 alkoxy group, a nitro, a cyano,
an amino, a C1-6monoalkylamino group or a C2-10 dialkylamino group;
and n represents 0 to 3.
2. An imidazo[1,2-a]pyrimidone derivative or a salt thereof, or a solvate
thereof or a hydrate thereof as claimed in claim 1 , wherein R1 represents an
unsubstituted 4-pyrimidine ring.
3. An imidazo[1,2-alpyrimiclone derivative or a salt thereof, or a solvate
thereof or a hydrate thereof as claimed in claim 1 or 2, a benzene ring, a
naphthalene ring, or a 5,6,7,8-tetrahydronaphthalene ring, the rings being
optionally substituted.
4. An imidazo[1,2-a]pyrimidone derivative which is selected from the
group consisting of:
• 1 -(3-Phenyl-propyl)-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-one;
• 1 -[3-(2-Fluoro-phenyl)-propyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 1 -[2-(4-Fluoro-2-methoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one;
• 1 -[2-(4-Methoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 1 -[2-(4-methyl-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 1 -(2-Naphthalen-1-yl-ethyl)-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 1 -[2-(3-Fluoro-phenyl)-ethyl]-7-(pyrirnidih-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 1 -[2-(3-Chloro-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 1 -[2-(2-Methoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 4-[2-[5-Oxo-7-(pyrimidin-4-yl)-5H-imidazo[1,2-a]pyrimidin-1 -yl]-ethyl]-
benzonitrile
• 1 -(2-Hydroxy-2-phenyl-ethyl)-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 1 -(2-Oxo-2-phenyl-ethyl)-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-one;
• 1 -[2-(4-Fluoro-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one;
• 1 -[2-(4-Ethoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-a]pyrimidin-5-
one; or
• 1 -[2-(2,5-Dimethoxy-phenyl)-ethyl]-7-(pyrimidin-4-yl)-1H-imidazo[1,2-
a]pyrimidin-5-one;
or a salt thereof, or a solvate thereof, or a hydrate thereof.
5. A 7-(pyrimidinyl)-imidazo[1,2-a]pyrimidin-5(1H)-one derivative of
formula (III):
wherein:
R1 represents a 2, 4 or 5-pyrimidinyl optionally substituted by a C1-4 alkyl group,
C1-4 alkoxy group or a halogen atom.
6. A medicament comprising as an active ingredient a substance selected
from the group consisting of an imidazo[1,2-a]pyrimidone derivative represented
by formula (I) or salts thereof, or a solvate thereof or a hydrate thereof as claimed
in claims 1 to 4.
7. A GSK3ß inhibitor selected from the group of a imidazo[1,2-
a]pyrimidone derivative represented by formula (!) or salts thereof, or a solvate
thereof or a hydrate thereof as claimed in claims 1 to 4.
8. A medicament as claimed in claim 6 for preventive and / or therapeutic
treatment of a disease caused by abnormal GSK3ß activity.
9. A medicament as claimed in claim 6 for preventive and / or therapeutic
treatment of a neurodegenerative disease.
10. A medicament as claimed in claim 9, wherein the
neurodegenerative disease is selected from the group consisting of Alzheimer"s
disease, Parkinson"s disease, tauopathies, vascular dementia; acute stroke,
traumatic injuries; cerebrovascular accidents, brain cord trauma, spinal cord
trauma; peripheral neuropathies; retinopathies or glaucoma.
11. A medicament as claimed in claim 6, for preventive and / or therapeutic
treatment of non-insulin dependent diabetes ; obesity ; manic depressive illness ;
schizophrenia ; alopecia ; or cancers.
12. A medicament as claimed in claim 11, wherein cancer is breast cancer,
non-small cell lung carcinoma, thyroid cancer, T or B-cell leukemia or virus-
induced tumors.
The invention relates to a imidazo[1,2-a]pyrimidone derivative represented by formula (1) or a salt thereof: R1
wherein X represents a bond, an ethenylenc group, an elhcnylene group, a methylene group optionally substituted; a carbonyl group,
an oxygen atom, a sulfur atom, a sulfonyl group, a sulfoxide group or a nitrogen atom being optionally substituted; R1 represents a
2, 4 or 5-pyrimidinyl optionally substituted; R: represents a C1-6 alkyl group, a C1-2 perhalogenated alkyl group, a C1-3 halogenated
alkyl group, a benzyl group, a benzene ring, a naphthalene ring. 5,6,7,8-tetrahydronaphthalene ring, a pyridine ring, an indole ring,
a pyrrole ring, a thiophene ring, a furan ring or an imidazole ring, the benzyl group and the rings being optionally substituted; and n
represents 0 to 3. The invention relates atso to a medicament comprising the said derivative or a salt thereof as an active ingredient
which is used for preventive and/or therapeutic treatment of a neurodegenerative disease caused by abnormal activity of GSK3b,
such as Alzheimer disease.

Documents:

1082-kolnp-2004-granted-abstract.pdf

1082-kolnp-2004-granted-assignment.pdf

1082-kolnp-2004-granted-claims.pdf

1082-kolnp-2004-granted-correspondence.pdf

1082-kolnp-2004-granted-description (complete).pdf

1082-kolnp-2004-granted-examination report.pdf

1082-kolnp-2004-granted-form 1.pdf

1082-kolnp-2004-granted-form 13.pdf

1082-kolnp-2004-granted-form 18.pdf

1082-kolnp-2004-granted-form 3.pdf

1082-kolnp-2004-granted-form 5.pdf

1082-kolnp-2004-granted-gpa.pdf

1082-kolnp-2004-granted-letter patent.pdf

1082-kolnp-2004-granted-reply to examination report.pdf

1082-kolnp-2004-granted-specification.pdf


Patent Number 214992
Indian Patent Application Number 01082/KOLNP/2004
PG Journal Number 08/2008
Publication Date 22-Feb-2008
Grant Date 20-Feb-2008
Date of Filing 29-Jul-2004
Name of Patentee SANOFI- AVENTIS AND MITSUBISHI PHARMA CORPORATION
Applicant Address 174, AVENUE DE FRAQNCE, F-75013 PARIS FRANCE
Inventors:
# Inventor's Name Inventor's Address
1 LOCHEAD ALISTAIR 95, RUE DE PARIS, F-94220 DCHARENTON LE PONT FRANCE
2 SAADY MOURAD 24, FAUBOURG SAINTANTOINE F-75012 PARIS, FRANCE
3 YAICHE PHILIPPE 2, PLACE MARCSAANGNIER F-93260 LEA LILAS FRANCE.
PCT International Classification Number C07D487/04
PCT International Application Number PCT/EP03/02652
PCT International Filing date 2003-02-26
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 02290487.4 2002-02-28 France