Title of Invention	"A COMPOUND SELECTED FROM DERIVATIVES OF FORMULA 1 THAT ARE INHIBITORS OF THE ENZYME OF DIPEPTIDYL PEPTIDASE IV"
Abstract	A compound selected from derivatives of formula 1 that are inhibitors of the enzyme of dipeptidyl peptidase IV, its tautomers and stereoisomers thereof, and pharmaceutically acceptable salts of said derivatives, tautomers and isomers wherein: X1 is selected from a sulphur atom, an oxygen atom, a sulphinyl group, a sulphonyl group and a methylene group; X2 is methylene; X3 is either a carbonyl or thiocarbonyl group; R1 is either a hydrogen atom or a nitrile group; R2and R3are independently selected from H and C1-C6 alkyl, or together may be -(CH2)P.; R4 is R6 R7 N; R6 and R7 are selected independently from R8(CH2)q or together they are -(CH2)2-Zt- (CH2)- or -CHR9 -Z2-CH2-CHR10-; R8 is selected from H, Ci-C6 alkyl, benzo- fused cyclo (CrC6)alkyl, (CrC6) alkyl-to acyl, di (C1-C6) alkylamino, N- (C1-C6)alkylpiperidyl, substituted aryl, optionally substituted alkylbenzyl, optionally substituted aroyl, and optionally substituted arylsulphonyl; R9 and R10 are selected independently from H, carbamoyl, hydroxymethyl and cyanomethyl: Z1 is selected from a covalent bond, -(CH2)r-, -0-, -SOt- and - N((CH2)qR8)-; Z2 is an optionally substituted ortho-phenylene moiety; m is 1 - 3; n is 0 - 4; p is 2 - 5; q is 0 - 3; r is I or 2; and t is 0 - 2; the optional substitutent(s), if present, being selected from (C1-C6) alkyl, aryl which may be further substituted with one or more methyl or trifluoromethyl groups, hydroxy, (C1-C6) alkyloxky, (C1-C6)alkylsulphonyl, acyl, perfluroacyl, amino, (C1-C6) alkylamino, di(C1-C6)alkyl amino, amino alkylene, fluoro, chloro, bromo, trifluoromethyl, nitro, cyano, carbamoyl, carboxy and (C1-C6) alkyloxycarbonyl group and/or where two adjacent substituents are present, the two adjacent substituents may be linked so as to form a ring fused to the parent aryl or heteroarylring.

Title of Invention

"A COMPOUND SELECTED FROM DERIVATIVES OF FORMULA 1 THAT ARE INHIBITORS OF THE ENZYME OF DIPEPTIDYL PEPTIDASE IV"

Abstract

A compound selected from derivatives of formula 1 that are inhibitors of the enzyme of dipeptidyl peptidase IV, its tautomers and stereoisomers thereof, and pharmaceutically acceptable salts of said derivatives, tautomers and isomers wherein: X1 is selected from a sulphur atom, an oxygen atom, a sulphinyl group, a sulphonyl group and a methylene group; X2 is methylene; X3 is either a carbonyl or thiocarbonyl group; R1 is either a hydrogen atom or a nitrile group; R2and R3are independently selected from H and C1-C6 alkyl, or together may be -(CH2)P.; R4 is R6 R7 N; R6 and R7 are selected independently from R8(CH2)q or together they are -(CH2)2-Zt- (CH2)- or -CHR9 -Z2-CH2-CHR10-; R8 is selected from H, Ci-C6 alkyl, benzo- fused cyclo (CrC6)alkyl, (CrC6) alkyl-to acyl, di (C1-C6) alkylamino, N- (C1-C6)alkylpiperidyl, substituted aryl, optionally substituted alkylbenzyl, optionally substituted aroyl, and optionally substituted arylsulphonyl; R9 and R10 are selected independently from H, carbamoyl, hydroxymethyl and cyanomethyl: Z1 is selected from a covalent bond, -(CH2)r-, -0-, -SOt- and - N((CH2)qR8)-; Z2 is an optionally substituted ortho-phenylene moiety; m is 1 - 3; n is 0 - 4; p is 2 - 5; q is 0 - 3; r is I or 2; and t is 0 - 2; the optional substitutent(s), if present, being selected from (C1-C6) alkyl, aryl which may be further substituted with one or more methyl or trifluoromethyl groups, hydroxy, (C1-C6) alkyloxky, (C1-C6)alkylsulphonyl, acyl, perfluroacyl, amino, (C1-C6) alkylamino, di(C1-C6)alkyl amino, amino alkylene, fluoro, chloro, bromo, trifluoromethyl, nitro, cyano, carbamoyl, carboxy and (C1-C6) alkyloxycarbonyl group and/or where two adjacent substituents are present, the two adjacent substituents may be linked so as to form a ring fused to the parent aryl or heteroarylring.

Full Text	Field Of Invention The present invention relaters to a compound selected from derivatives of formula 1 that are inhibitors of the enzyme of dipeptidyl peptidase IV. Background The enzyme dipeptidyl peptidase IV, herein abbreviated DP-IV (and elsewhere as DAP-IV or DPP-IV) and also known by the classification EC.3. 4.14.5, is a serine protease that cleaves the N-terminal dipeptide from peptides that begin with the sequence H-Xaa-Pro (where Xaa is any amino acid, although preferably a lipophilic one, and Pro is proline). It will also accept as substrates peptides that begin with the sequence H-Xaa-Ala (where Ala is alanine). DP-IV was first identified as a membrane-bound protein. More recently a soluble form has been identified. Initial interest in DP-iV focussed on its role in the activation of T lymphocytes. DP-IV is identical to the T cell protein CD26. It was proposed that inhibitorsof DP-IV would be capable of modulating T cell responsiveness, and so could be developed as novel immunomodulators. It was further suggested that CD26 was a necessary co-receptor for HIV, and thus that DP-IV inhibitors could be useful in the treatment of AIDS. Attention was given to the role of DP-IV outside the immune system. It was recognised that DP-IV has a key role in the degradation of several peptide hormones, including growth hormone releasing hormone (GHRH) and glucagonlike peptide-1 and -2 (GLP-1 and GLP-2). Since GLP-1 is known to have a potentiating effect on the action of insulin in the control of post-prandial blood glucose levels it is clear that DP-IV inhibitors might also be usefully employed in the treatment of type 11 diabetes and impaired glucose tolerance. At least two DP-IV inhibitors are currently undergoing clinical trials to explore this possibility. Several groups have disclosed inhibitors of DP-IV. While some leads have been found from random screening programs, the majority of the work in this field has been directed towards the investigation of substrate analogs. Inhibitors of DP-IV that are substrate analogs are disclosed in, for example, US 5,462,928, US 5,543,396, WO 95/15309 (equivalent to US 5,939,560 and EP 0731789), WO 98/19998 (equivalent to US 6,011,155), W099/46272 and .W099/61431. The most potent inhibitors are aminoacyf pyrrolidine boronic acids, but these are unstable and tend to cyclise, while the more stable pyrrolidine and thiazolidine derivatives have a lower affinity for the enzyme and so would require large doses in a clinical situation. Pyrrolidine nitriles appear to offer a good compromise since they have both a high affinity for the enzyme and a reasonably long half-life in solution as the free base. -There remains, however, a need for inhibitors of DP-IV with improved properties. Brief Description of the Invention The present invention relates to a series of inhibitors of DP-IV with improved affinity for the enzyme. The compounds can be used for the treatment of a number of human diseases, including impaired glucose tolerance and type II diabetes. Accordingly, the invention further relates to the use of the compounds in the preparation of pharmaceutical compositions, to such compositions per Se, and to the use of such compositions in human therapy. The compounds of the invention are described by general formula 1. (Formula Removed) ln general formula I, X' is selected from —S-., -0.-, -SO-, -SOT and —CHT; X2 is selected from —0-, -5-, -NH- and —CHT; X3 is either -NR5- or a >00 or >0=5 group; R' is either H or -ON; R2 and R3 are independently selected from H and lower alkyl, or together may be -(CH2)~-; R4 is R4A when X3 is -NR5- and R4B when X3 is >0=0 or >C=S; R~ is selected from R6R7NC(=O), R6RTNC(=S); R8(CH2)qC(=O), R8(CH2)qC(5), R8(0H2)qSO2, R8(CH2)qOC(5) and R8(0H2)qOC(=O); R4B is R6R7N; R5 is H or lower alkyl; R8 and R7 are each independently R8(0H2)q or together they are —(0H2)TZ-(0H2)T; R8 is selected from H, alkyl, optionally substituted aryl, optionally substituted aroyl, optionally substituted arylsulphonyl and optionally substituted heteroaryl; Z is selected from a covalent bond, ~~; n is 0—4; p is 2—5; q is 0—3; r is I or 2; and t is 0 Detailed Description of the Invention In a first aspect, the present invention comprises a series 6f novel compounds. that are inhibitors of the enzyme DP-IV and are useful for the treatment of certain human diseases. The compounds are described by general formula I. (Formula Removed) In general formula I, X1 is a divalent group selected from a sulphur atom (—5-), an oxygen atom (-0-), a suiphinyl group (-SO-), a suiphonyl group (-SOT) and a methylene group (-OH,.-). X2 is a divalent group selected from an oxygen atom (—0-), a sulphur atom (-5-) and a methylene group (—OH,.-). X3 is either a substituted imino group (-NR5-) or a carbonyl (>0=0) or thiocarbonyl (>0=5) group. R' is either a hydrogen atom (H) or a nitrile group (-ON). R2 and R3 may each independently of the other be a hydrogen atom or a lower alkyl group, or together they may be a chain of between two and five methylene units (-(OH,.)~- where p is in the range 2 — 5) so as to form, with the carbon atom to which they are attached, a three,-four, five or six-membered ring. The value of m may be 1, 2 or 3. When m is greater than I then each 0R2R3 unit may be the same or different. For example, when m is 2 then (0R2R3),. may be OH,.OH,., OH,.O(Me),., O(Me),.OH,. and the like. The nature of R4 depends on the identity of X3, such that the two groups are linked by an amide (CO-N), thioamide (05-N) or sulphonamide (SO,..-N) bond. So, when X8 is a substituted imino group (-NR5-) then R4 is ~ where R4A is selected from carbamoyl groups (R6R7NC(=O)), thiocarbamoyl groups (R6R7NO(=S)); optionally modified acyl groups (RNOI~l~)qO(=O)), optionally modified thioacyl groups (R8(CH2)qOQ~S)), sulphonyl groups (R8(CHz)qSO2), optionally modified (alkyl or aryloxy)carbonyl groups (R8(CH2)qOO(0)) and optionally modified (alkyl or aryloxy)thiocarbonyl groups(R8(CH,.)qOC(=S)). As used herein, the tern, "optionally modified" is taken to indicate that some embodiments of R8 are beyond the scope of the terms '~alkyl~, "acyr and "aryl". The scope of the definition of R'~ is determined by the scope of the definition of RB. Alternatively, when X3 is a carbonyl (>0=0) or thiocarbonyl (>C~S) group then R4 is R48, where R4B is a substituted amino group (R8R7N). R5 is a hydrogen atom (H) or a tower alkyl group. Preferably, R5 is H. R8 and R7 may each independently of the other be R8(CH2)q. Alternatively, they may together be a group —(OH,.),.-Z1-(CH,.),.- or —CHR9-Z2-CH,.--OR'0-. Here Z' is a covalent bond, a methylene or ethylidene group (-(OH~- where r is I or 2), an oxygen atom (-0-), a sulphur or oxidised sulphur atom (-SOr where t is zero, I or 2) or a substituted imino group (~N((CH2)qR8)), such that the group NR6R7 is a pyrrolidine, piperidine, perhydroazepine, morpholine, optionally oxidised thiomorpholine or substituted piperazine ring. Z2 is an ortho-phenylene moiety (—C6H4--), such that the group NR6R7 is a tetrahydroisoquinoline. R8 is selected from a hydrogen atom (H), a lower alkyl group, a benzo-fused lower cycloalkyl group (such as an indanyl group), an acyl (lower alkyl-CO) group, a di(lower alkyl)amino group, a di(lower alkyl)carbamoyl group, an N-(lower aIkyl)piperidinyl group, an optionally substitiued a-alkylbenzyl group, an optionally substituted phenyl, naphthyl or heteroaryl group, and an optionally substituted aroyl (aryl-CO) or arylsulphonyl (aryl-S02) group. In the foregoing, suitable optional substituents are lower alkyl, aryl which may be further substituted with one or more methyl or trifluoromethyl groups, hydroxy, lower alkyloxy, lower alkylsulphonyl, acyl, perfiuoroacyl, amino, lower alkylamino, di(lower alkyl)amino, aminoalkylene, fluoro, chloro, bromo, trifluoromethyl, nitro, cyano, carbamoyl, carboxy and lower aikyloxycarbonyl groups. In addition, two adjacent substituents may be linked so as to form a ring fused to the parent aryl or heteroaryl ring. R9 and R10 are independently selected from hydrogen, carbamoyl, hydroxymethyl and cyanomethyl groups. The integer n is selected from the range zero to 4, and q is selected from the range zero to 3. Certain compounds are specifically excluded from the scope of the present invention. When X2 is methylene, X3 is NH and R4 is R8(CHz)qO(CO), with q = , then R8 may not be unsubstituted phenyl or phenyl substituted with a nitro group. It is generally preferred that when X2 is methylene, X3 is NH, R4 is R8(CH2)qQ(OO), q is I and RB is a substituted phenyl group then the substituent or substituents should be selected from chloro, methoxy and trifluoromethyl groups. In the context of the present disclosure, the term lower alkyl, either by itself or in such combinations as lower alkyloxy, is intended to comprise linear, branched and cyclic saturated hydrocarbon groups of between one and six carbon atoms. Examples of lower alkyl groups include, but are not limited to, methyl, ethyl, isopropyl, tert-butyl, neopentyl, cyclohexyl, cyclopentylmethyl, 2-(cyclopropyl)ethyl, 3,3-dimethylcyclobutyl and bicyclo[3. 1 .Ojhexyl. The term heteroaryl includes monocyclic five- and six-membered ring aromatic groups with one or two heteroatoms, which are selected from nitrogen, oxygen and sulphur. Thus, heteroaryl groups include pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, pyrrolyl, thienyl, furyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl and isoxazolyl. Heteroaryl further includes the benzofused derivatives of these rings, such as quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, phthalazinyl, cinnolinyt, indolyl, isoindofyf, benzothiazolyl and the like, and bicyclic groups formed by the fusion of two such monocyclic heteroaromatic groups. The term aryl includes phenyl, naphthyl and heteroaryl. The compounds of general formula I have at least one stereogenic centre and so can exhibit optical isomerism. All such isomers, including enantiomers, diastereomers and epimers are included within the scope of the invention. Furthermore, the invention includes such compounds as single isomers and as ~mixtures, including racemates. Certain compounds according to general formula, including those with a heteroaryl group which carries a hydroxy or amino substituent, can exist as tautomers. These tautomers, either separately or as mixtures, are also considered to be within the scope of the invention. The compounds according to general formula I have at least one basic functional group. They can therefore form addition salts with acids. Those addition salts that are formed with pharmaceutically acceptable acids are included within 'the scope of the invention. Examples of suitable acids include acetic acid, trifluoroacetic acid, citric acid, fumaric acid, benzoic acid, pamoic acid, methanesulphonic acid, hydrochloric acid, nitric acid, sulphuric acid, phosphoric acid and the like. Certain compounds according to general formula I have an acidic group and so are able to form salts with bases. Examples of such salts include the sodium, potassium and calcium salts, which are formed by the reaction of the acid with the corresponding metal hydroxide, oxide, carbonate or bicarbonate. Similarly, tetra-alkyl ammonium salts may be formed by the reaction of the acid with a tetra-alkyl ammonium hydroxide. Primary, secondary and tertiary amines, such as triethylamine, can form addition salts with the acid. A particular case of this would be an internal addition salt formed between an acidic group and the primary amine group of the same molecule, which is also called a zwitterion. Insofar as they are pharmaceutically acceptable, all these salts are included within the scope of the invention. In a preferred embodiment of the invention R1 is a nitrile group. Within this embodiment, it is preferred that the stereochemistry of the nitrile group is as shown in general formula 2. (Formula Removed) According to the standard terminology, this is the S configuration when X' is methylene but the R configuration when X1 is sulphur, oxygen, sulphinyl or sulphonyl. In another preferred embodiment, the stereochemistry at the centre adjacent to the primary amine is as shown in general formula 3. This is the S configuration when X2 is an oxygen atom or a methylene or imino group, and the R configuration when X2 is a sulphur atom. (Formula Removed) Within this embodiment, it is more preferred that R1 should be a nitrile group, and more preferred still that it should have the absolute configuration depicted in general formula 4. (Formula Removed) In another preferred embodiment of the invention, m is 1. More preferably m is I and R2 and R3 are independently hydrogen atoms or methyl groups. When X2 is a methylene group, it is more preferred that R2 and R3 both be hydrogen. When X2 is an oxygen atom, it is more preferred that one of R2 and R3 be hydrogen and the other a methyl group. When X2 is a sulphur atom, it is more preferred that both R2 and R3 be methyl groups. In another preferred embodiment, X1 is either S or methylene. More preferably, X1 is S and R' is H, or K1 is methylene and R1 is CN. In another preferred embodirnent, X3 is NH. More preferably. X3 is NH, m is 1, R2 and R3 are both H, X2 is methylene and n is I or 2. In another preferred embodiment, R4 is R8NHCO or R800 and R8 is an optionally substituted heteroaryl group. More preferably, R5 is an unsubstituted heteroaryl group, or a heteroaryl group substituted with one or two groups chosen from lower alkyl, lower alkyloxy, fluoro, chioro and trifluoromethyl groups. In another preferred embodiment, X3 is 00 and R4 is R6NH. More preferably R8 is an optioriaUy substituted heteroaryl' group. More preferably still, R5 is an unsubstituteci heteroaryl group, or a heteroaryl group substituted with one or two groups chosen from lower alkyl, lower alkyloxy, fluoro, chloro and trifluoromethyl groups. In another preferred embodiment, X3 is NH and R4 is selected from R6R7N(O0), R8(0H2)qCO and R8(CH2)q502. Particularly preferred compounds within the invention include: (2S)-l-[AP-(Pyrazinyk2-carbonyl)..L.-ornithinyl]pyrroIidine.-zca~onftgile, (2S)-1 -[N~-(Pyrazinyl-2-carbonyl)..L.-lysinyI]pyrrolidine..2~carbonjtrile, (2S)4{(2tS)-21-Amino-4'-(pyrazinyl..V..cabonylamino)butanoylJpyrm1idine-~ca~-~nj.jjfe (4R)-3-[Nm-(Pyrazinyl-2-carbonyi).-L.-iysinyl]thiazolidine4.carbonitrije, (2S)-l-IAP-(Pyridyl-3-methy~-L.-glutaminy~pyrrolicune.-2~carbot,itrife, I -[N~-(Pyrazinyl-2-carbonyl)-L-omithinyl]pyrrolidine, (2S)-1 -[S-(Acetylaminomethyl)..L-cysteinyl]pyrroliciine..2~carbonitriIe, 3-ENm-(2-Ohloropyridyl-3-carbonyl).-L-omithinyqthiazolidine, I ~ and 3-1N0-(Pyrazinyl-2-carbonyl)-L.-ornithinyljthiazolidine, 3-[IV'0-(2-Quinoxaloyl~L.-lysinyl]thiazolidine 3-~N"'-(2-QuinoxaIoyI)-L-omithinyl]thiazolidine~ (25)-I -(N~-(2-Quinoxaloyl)-L-ornithinylJpyrroJidine-2-carbonitrile, 3..fN"..(6..Methylpyrazinyl-2..carbonyl)..L..ornithinyl]thiazolidine, 3-[i%f~-(lsoquinoline-3-carbonyl).-L-.omithinyl]thiazolidine, 3-[Af-(B-Trifluoromethylnicotinoyl)4...omithinyl]thiazolidine, (2S)-I -[(2'R)-3'-(Acetylaminomethylthio)-2-amino-3'-methylbutanoyl]pyrrolidine-2.. carbonitrile, (2S)-I -[S-(3-Piolylcarbamoylmethyl>.L-cysteinyl]pyrrolidine-2-carbonitrile, 3-{Ar-(3-Pyridyloxycarbonyl)-L-omithinyrjthiazolidine, 3-[O-(3-Chlorobenzylcarbamoyl)seiinyl]thiazolidine, and 3.{(2'S).2'..Amino-5'..oxo..5'..{I ",2",3" ,4"-tetrahydroisoquinolin-2"-yl)pentanoyl]thiazolidine. In a second aspect, the present invention comprises a pharmaceutical composition for human therapeutic use. The composition is charactetised in that it has, as an active agent, at least one of the compounds described above. Such a composition is useful in the treatment of human diseases. The composition will generally include one or more additional components selected from pharmaceutically acceptable excipients and pharmaceutically active agents other than those of the present invention. The composition may be presented as a solid or liquid formulation, depending on the intended route of administration. Examples of solid formulations include pills, tablets, capsules and powders for oral administration, suppositories for rectal or vaginal .administration, powders for nasal or pulmonary administration, and patches for transdermal or transmucosal (such as buccal) administration. Examples of liquid formulations include solutions and suspensions for intravenous, subcutaneous or intramuscular injection and oral, nasal or pulmonary administration. A particularly preferred presentation is a tablet for oral administration. Another preferred presentation, particularly for emergency and critical care, is a sterile solution for intravenous injection. The composition comprises at least one compound according to the preceding description. The composition may contain more than one such compound, but in general it is preferred that it should comprise only one. The amount of the compound used in the composition will be such that the total daily dose of the active agent can be administered in one to four convenient dose units. For example, the composition can be a tablet containing an amount of compound equal to the total daily dose necessary, said tablet to be taken once per day. Alternatively, the tablet can contain half (or one third, or one quarter) of the daily dose, to be taken twice (or three or four times) per day. Such a tablet can also be scored to facilitate divided dosing, so that, for example, a tablet comprising a full daily dose can be broken into half and administered in two portions. Preferably, a tablet or other unit dosage form will contain between 0.1mg and Ig of active compound. More preferably, it will contain between 1mg and 250mg. The composition will generally include one or more excipients selected from those that are recognised as being pharmaceutically acceptable. Suitable excipients include, but are not limited to, bulking agents, binding agents, diluents, solvents, preservatives and flavouring agents. Agents that modify the release characteristics of the composition, such as polymers that selectively dissolve in the intestine ("enteric coatings") are also considered in the context of the present invention, to be suitable excipients. The composition may comprise, in addition to the compound of the invention, a second pharmaceutically active agent. For example, the composition may include an anti-diabetic agent, a growth-promoting agent, an anti-inflammatory agent or an antiviral agent However, it is generally preferred that the composition comprise only one active agent In a third aspect, the invention comprises a use for the compounds and compositions described above for the treatment of human diseases. This aspect can equally be considered to comprise a method of treatment for such, diseases. The diseases susceptible to treatment are those wherein an inhibition of DP-IV or CD26 results in a clinical benefit either directly or indirectly. Direct effects include the blockade of T lymphocyte activation. indirect effects include the potentiation of peptide hormone activity by preventing the degradation of these hormones. Examples of diseases include, but are (Formula Removed) not limited to, auto-immune and inflammatory diseases such as inflammatory bowel disease and rheumatoid arthritis, growth hormone deficiency leading to short stature, polycystic ovary syndrome, impaired glucose tolerance and type 2 diabetes. Particularly preferred is the use of the compounds and compositions for the treatment of impaired glucose tolerance and type 2 diabetes, and equally a method of treatment of these diseases by the administration of an effective amount of a compound or composition as previously described. The precise details of the treatment, including the dosing regimen, will be established by the attending physician taking into account the general profile of the patient and the severity of the disease. For diseases such as inflammatory bowel disease that have acute phases of active disease separated by quiescent periods, the physician may select a relatively high dose during the acute phase and a tower maintenance dose for the quiescent period. For chronic diseases such as type 2 diabetes and impaired glucose tolerance, the dosing may need to be maintained at the same level for an extended period. A dosing schedule of one to four tablets per day, each comprising between 0.1mg and Ig (and preferably between 1mg and 250mg) of active compound might be typical in such a case. The compounds according to the invention can be prepared by methods known in the art. The route chosen will depend on the particular nature of the substituents present in the target molecule. In the following general description the synthetic route is outlined for compounds wherein m is 1. Compounds with m = 2 or 3 can generally be prepared by analogous routes. The starting material will usually be an c,co-diamino acid derivative 5 or an amino dicarboxylic acid derivative 6. (Formula Removed) PG' and PG2 are "orthogonal" protecting groups — groups that mask the reactivity of the amine groups and that can each be selectively removed in the presence of the other. Suitable groups are well known in the literature. PG3 and PG4 are protecting groups for carboxylic acids. They are chosen such that they are orthogonal to each other and to the amino protecting groups. Suitable possibilities for PG3 and PG4 are also well known in the literature. Derivatives of diamino acids according to general formula 5 and derivatives of amino dicarboxylic acids according to general formula 6 are either items of commerce, or can be prepared following methods described in the literature. In practice, and depending on the strategy chosen, the starting material will have only two of the three protecting groups present. Either PG3 will be absent to allow the pyrrolidine (or thiazolidine or oxazolidine) residue to be introduced, or PG' or PG4 will be absent to allow the side chain to be elaborated. Scheme A illustrates the introduction of the pyrrolidine (or thiazolidine or oxazolidine) group as the first step in the preparation of the compounds of the invention. Scheme A (Scheme Removed) Compounds 5A and 6A correspond to 5 and 6 with PG3 as a hydrogen atom (i.e. without the protecting group). The free carboxylic acid can be reacted with a pyrrolidine derivative 7 to give the amide 8 or 9. Reaction conditions for achieving this transformation are well (Formula Removed) known in the literature. Suitable reagents include carbodiimides, phosphorus reagents and alkyl chloroformates, and the reaction is usually catalysed by a tertiary amine such as triethylamine or dimethylaminopyridine. The reaction depicted in Scheme A is available for all combinations of R1 and K'. However, for the case where R' is a nitnle group, or where K' is a sulphinyl or sulphonyl group, it may be advantageous to modify the strategy as depicted in Schemes B and 0. Scheme B (Scheme Removed) ln Scheme B, the R1 group is introduced as a primary amide and subsequently transformed into a nitrile by the action of a dehydrating agent such as trifluoroacetic anhydulde. In Scheme C, the K' group is introduced as a thioether and subsequently transformed into a sulphoxide (a=1) or sulphone (a=2) by the action of an oxidant such as sodium periodate. The modification to the strategy afforded by Scheme C is not possible if X2 is a sulphur atom. Scheme D (Scheme Removed) ln Scheme D, compound 5D is the diamino acid derivative 5 where the a-protecting group is a hydrogen atom. The free amine group reacts readily with sulphonyl chlorides, acyl chlorides and thicacyl chlorides, usually in the presence of a tertiary amine. to produce sulphonarnides 14, amides 15 and thicamides 16 respectively. The reagents are generally either available per se, or can be prepared from the corresponding acids. The reaction of scheme D is generally applicable to all the variations of the group R8(CI~l2)q, with the proviso that certain of the substituents contemplated for the phenyl and heteroaryl rings which are options for RB may require, protection. Such substituents and the appropriate protection will generally be obvious to those familiar with the art. Scheme E (Scheme Removed) Reagents: i) COCJ,.; ii) 05C12; iii) R8(CH,.)qOH; iv) R6R7NH; v) R8(CH,.)qOOOOl; vi) R8(CH2)qOCSCI; vii) R8R7NCOCI; viii) R5R7NCSCI. Scheme E illustrates the elaboration of 50 to give carbamates and ureas, and their thio analogues. When R5 is other than a hydrogen atom, compound ~D can be converted to the corresponding carbamoyl chloride 17 or thiocarbamoyl chloride 18 by reaction with phosgene or thiophosgene. Other reagents are known in the art to be functionally equivalent to these toxic reagents and they may also be used. When R5 is hydrogen, the intermediate formed is an isocyanate or isothiocyanate, but this behaves functionally as an equivalent of the corresponding chloride. Intermediates 17 and 18 are not normally isolated, but are treated directly with alcohols to give carbamates 19 and thiocarbamates 20. Treatment of these same intermediates with amines leads to the formation of ureas 21 and thioureas 22. Alternatively, 50 may be reacted directly with a chloroformate or chlorothioformate to give the carbamate or thiocarbamate, or, when neither R6 nor R7 is hydrogen, with a chloroformamide or chlorothioformamide to give the urea or thiourea. When R6 or R7 is a hydrogen atom the chloroformamide or chlorothioformamide will tend to be unstable, in which case the isocyanate (e.g. R8-NCO) or isothiocyanate (e.g. R8-NCS) is used. As discussed previously for Scheme D, certain substituents within the embodiments of RB may require appropriate protection. Scheme F(Scheme Removed) Scheme F illustrates the elaboration of the side chain of the amino dicarboxylic acid series. The ~-deprotected acid 6F can be reacted under a variety of conditions with an amine to give amide 23. The condensation may be promoted by a dehydrating reagent such as a carbodiimide or a phosphorus reagent. Alternatively the acid may be converted into a more reactive derivative, such as by treatment with oxalyl chloride or thionyl chloride to give the corresponding acid chloride, which will react directly with an amine. The thicamide 24 may be obtained by treating the amide 23 with Lawesson's reagent When all the groups have been elaborated the final protecting group is removed and the product is isolated and purified using standard techniques. These general methods are further illustrated in the following, non limiting examples. EXAMPLES Abbreviations The following abbreviations have been used. DMF N,N-Dimethyformamide h Hour(s) hplc High pressure liquid chromatography mm Minute(s) pet ether Petroleum ether fraction boiling at 6O~8OoO PYBOP (Benzotriazol-1 -yloxy)tripyrrolidinophosphonium hexafluorophosph ate PyBroP Bromotripyrrolidinophosphonium hexafluorophosphate TFA Trifluoroacetic acid EXAMPLE I (2S)-1 -[N~-(Pyrazinyl-2-carbonyl)-L-ornithinyI]pyrrolidine-2-carbonitrile trifluoroacetate (Formula Removed) A. N-(2-Nitrobenzenesulphenyl)-L-proline L-Proline (25g, 2l7mmol) was dissolved in 2M NaCH (1 lOmL, 22Ommol) and dioxan (i2OrnL). A solution of 2-nitrobenzenesulphenyl chloride (42g, 222mmo1) in dioxan (GOmL) was slowly added at the same time as 2M NaOH (1 lOmL, 22Ommol). After 2h at room temperature the reaction mixture was poured into water (500mL) and the solid filtered off. The pH of the filtrate was adjusted to pH3 with 2M HOl and the solution was extracted with ethyl acetate (3 x 500mL). The combined organic extracts were washed with water (4 x 200mL) and brine (1 x 200mL), dried (Na,.504) and evaporated in vacua to give an orange solid identified as N-(2-nitrobenzenesulphenyl)-L-proline (58.lg, 2l7mmol, 100%). B. N-(2-Nitrobenzenesulphenyl)-L-proline succinimidyl ester N-(2-Nitrobenzenesulphenyl>-L-proline (57.9g, 2l6mmol) was dissolved in CH,.CI,.IDMF (9:1, 500mL). N-Hydroxysuccinimide (37.3g, 324mmo1) and water-soluble carbodiimide (51 .8g, 26Ommol) were added. After I 8h at room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (1 OOOmL). The solution was washed with water (4 x 200mL) and brine (1 x 200mL), dried (Na,.504) and evaporated in vacua to give a yellow solid identified as N-(2-nitrobenzenesulphenyl)-L-proline succinimidyl ester (78.9g, 2l6mmol, 100%). C. N-(2-Nitrobenzenesulphenyl)-L-prolinamide N-(2-Nitrobenzenesulphenyl)-L-proline succinimidyl ester (78.5g, 21 5mmol) was dissolved in dioxan (500mL). Ammonia (35%, 1 OOmL) was added. After stirring at room temperature for 2h the reaction mixture was poured into water (700mL). The precipitate was filtered off, washed with water (200niL), dried over P,.06 and recrystallised from ethyl acetate/pet ether to give a yellow solid identified as N.-(2-nitrobenzenesulphenyl)-L-prolinamide (49.Gg, l85mmoI, 88%). D. (2S)-N-(2-Nitrobenzenesulphenyl)pyrrolidine-2-carbonitrile N-(2-Nitrobenzenesulphenyl)-L-prolinamide (49g, lB3mmol) was dissolved in dry THF(300mL). The solution was cooled to 00C, triethylamine (36.7g. 367mmo1) was added followed by the slow addition of trifluoroacetic anhydride (77g, 367mmo1). The pH was adjusted to pH9 with triethylamine. After 30mm the reaction mixture was diluted with ethyl acetate (500mL), washed with water (1 x 200mL) and brine (1 x 200mL), dried (Na,.504) and evaporated in vacua to give an orange oil which was purified by flash chromatography (eluant: 80% pet ether, 20% ethyl acetate) to give a yellow solid identified as (2S)-N-(2-nitrobenzenesulphenyl)pyrrolidine-2-carbonitrile (38. 9g, I 5Ommol, 82%). E. (2S)-PyrroBdine-2-carbon itrile hydrochloride (2S)-N-(2-Nitrobenzenesulphenyl)pyrrolidine-2-carbonitrile (38.5g, 1 49mmol) was dissolved in diethyl ether (200mL). 4M HClIDioxan (1 5OrnL, 600mmol) was slowly added. After 2h at room temperature the reaction mixture was poured into diethyl ether (1 OOOmL). The solid was filtered off, washed with diethyl ether (500rnL) and recrystallised from methanol/diethyl ether to give a white solid identified as (2S)-pyrrolidine-2-carbonitrile hydrochloride (18.9g. 142.Smmol, 96%). F. (2S)-1 -ft?-(tert-Butyloxycarbonyl)-N~-(pyraziny1-2-carbonyl)-L-omithinyl]-pyrrofidine-2-carbonitrile. I'f~-(tert-Buloxycarbonyl)-AP-(pyrazinyl-2-carbonyl)-L-omithine (2.5g. 7.4mmol) was dissolved in CH,.C12 (5OmL). This solution was cooled to 000, (2S)-pyrrolidine-2-carbonitrile hydrochloride (1 .2g, 9.1 mmol) and PyB0P~' (4.3g, 8.23mmol) were added, and the pH adjusted to pH9 with triethylamine. After 1 8h at 000 to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (200mL). This solution was washed with 0.3M KHSO4 (2 x 5OmL), sat. NaHCO3 (2 x SOmL), water (2 x 5QmL) and brine (1 x 5OmL), dried (Na,.S04) and evaporated in vacuo to give a yellow oil. This was purified by flash chromatography (eluant 80% ethyl acetate, 20% pet. ether) to give a colourless oil identified as (2S)-1-[N~. G. (2S)-1 -[N~-(pyrazinyI-2-carbonyl)-L-omithiny~pyrrolidine-2-carbonitrile trifluoroacetate (2S)-1 -[IV~-te,1-Butyloxycarbony-(pyrazinyl-2-carbonyl)-L-ornithiny~pyrrolidine-2~ carbonitrile (2.Bg, 6.7mmol) was dissolved in trifluoroacetic acid (5mL). After I h at room temperature the solvent was removed in vacuo. The residue was purified by preparative hplc (Vydac -Cl 8, 5 to 50% 0.1% TFAIa:: atonitrile into 0.1 % TFNwater over 40mm at 3mllmin). Fractions containing the product were lyophilised to give a colourless oil identified as (2S)-1-[iV0-(pyrazinyl-2-carbonyl)-L-omithinylJpyrrolidine-2-carbonitrile trifluoroacetate (1 .5g, 3.48mmol, 52%). [M+HJ~ = 317.3 EXAMPLE 2 (2S)-1 -~Nm-(Pyrazinyl-2-carbonyI)-L-lysinyl]pyrrolidine-2-carbonitrile trifluoroacetate (Formula Removed) A. (N~-(tert-Butyloxycarbonyl)-N~-(9-fiuorenylmethyloxycarbonyI)-L-lysinyl)-L- prolinamide IV'-(tert-Butyloxycarbonyl)-N'9-(9-fluorenylmethyloxycarbonyl)-L-lysine (5g, I 0.7mmol) was dissolved in CH,.CI,. (IOOmL). The solution was cooled to 000, L-prolinamide (1 .78g, 11 .7mmol) and PyBOP (6.7g, I 2.8mmol) were added, and the pH adjusted to pH9 with triethylamine. After I 8h at 000 to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (200mL). The solution was washed with O.3M KHSO4 (2 x 5OmL), sat. NaHCO3 (2 x 5OmL), water (2 x 5OmL) and brine (I x 5OmL), dried (Na,.S04) and evaporated in vacuo. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (I-(te,t-butyloxycarbonyl)-N0-(9-fluorenyJmethyloxycarbonyl)-L-lysinyl)-L-prolinamide (4.05g, 7.2mmol, 67%). B. (2S)-1 -(N~-(tefl-ButyloxycarbonyI)-N"'-(9-fluorenylmethyIoxycarbcrnyI)-L-lysinyl)-pyrrolidine-2-carbonitrile (Af1-(tert-Butyloxycarbonyl)-Af0-(9-fluorenylmethyloxycarbonyl)-L-lysinyl)-L-prolinamide (3.95g, 7.O2mmol) was dissolved in dry Ti-IF (1 OOmL). The solution was cooled to 000, triethylamine (I .4g, I4mmol) was added followed by the slow addition of trifluoroacetic anhydride (2.97g, 14.1 mmol). The pH was adjusted to pH9 with triethylamine. After 30mm the reaction mixture was diluted with ethyl acetate (I OOmL), washed with water (I x 5OmL) and brine (1 x SGmL), dried (Na,.S04) and evaporated in vacuo to give an orange oil. The residue was purified by flash chromatography (eluant: 60% pet ether, 40% ethyl acetate) to give a colourless oil identified as ~ fluorenylmethyloxycarbonyl)-L-lysinyl)pyrrolidine-2-carbonitrile (3.3g. 6.11 mmol, 87%). C. (2S)-1 ..(Nz~(tert~ButyloxycarbonyI)~L~lysinyl) pyrrolidine-2-carbonitrile (2S)-1 ..(I~f~(teft-Butyloxycarbonyl)-m-(9-fluorenylmethyloxycarbonyl)-L-IysinyI)pyrrolidine- 2-carbonitrile (3.1 g, 5.7mmol) was dissolved in THF (8OmL). Diethylamine (2OmL) was added. After 2h at room temperature the solvent was removed in vacua. The residue was purified by flash chromatography (eluant: 90% chloroform, 7% methanol, 3% triethylamine) to give a colourless oil identified as (2S)-1-(N~-(tert-butyloxycarbonyl)-L-lysinyl)pyrrolidine-2-carbonitrile (1 .63g, 5.O3mmol, 89%). D. (2S)-1 -(Af~-(tert-Butyloxycarbonyl)-Nm-(pyrazinyl-2-carbonyl)-L-Iysinyl)pyrrolidine-2-carbonitrile (2S)-1-(AJ1-(tert-Butyloxycarbonyl)-L-lysinyl)pyrrolidine-2-carbonitrile (100mg, 0.31 mmol) was dissolved in CH,.CYDMF (9:1, 2OmL). To this solution at 00C was added 1-hydroxybenzotriazole hydrate (84mg, 0.62mmol), water-soluble carbod~mide (76mg, O.38mmol), 2-pyrazinecarboxylic acid (43mg, O.3Smmol) and triethylamine (65mg, 0.O5mmoI). After 18 h at 00C to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL). This solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHOO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua to give a yellow oil. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (2S)-1 -(AP-(te,t-butyloxycarbonyl)-W0-(pyrazinyl-2-carbonyl)-L-lysinyl)pyrrolidine-2-carbonitrile (1 24mg, 0.29mmol, 93%). E. (2S)-1 -~N"-(Pyrazinyl-2-carbonyI)-L-lysinyl]pyrrolidine-2-carbonitrile trifluoroacetate (2S)-1 -(M'-(tert-ButyloxycarbonyI)-N~-(pyrazinyl-2-carbonyl)-L-lysinyOpyrroIidine-2- carbonitrile (110mg, O.26mmol) was dissolved in trifluoroacetic acid (5mL). After I h at room temperature the solvent was removed in vacuo. The residue was purified by preparative hplc (Vydac 018, 5 to 50% 0.1% TFA/acetonitrile into 0.1% TFAlwater over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a colourless oil identified as (2S)-1 ..U~r.-(pyrazinyl-2-carbonyl)-L-lysinylJpyrrolidine-2-carbonitrile trifluoroacetate (66mg). (Formula Removed) EXAMPLE 3 (4R)-3-[N'-(Pyrazinyl-2-carbonyl)-L-lysinyljthiazolidine-4-carbonitrile trifluoroacetate (Formula Removed) A. (4R)-3-(tert-Butyloxycarbonyl)thiazolidine-4-carboxamide (4R)-3-(ted-Butyloxycarbonyl)thiazolidine-4-carboxylic acid (1 2.5g,54. I mmol) was dissolved in OH,.Cl,. /DMF (9:1, 1 5OmL). To this solution at 00C was added 1-hydroxybenzotriazole hydrate (14.6g, lO8mmol) and water-soluble carbodiimide (13.Og, GSmmol). After I h at 000 ammonia (35%, 5OmL) was added. After I 8h at O~C to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (500mL). The solution was washed with 0.3M KI-1504 (2 x I OOmL), sat. NaHCO3 (2 x lOOmL), water (2 x lOOmL) and brine (1 x lOOmL), dried (Na,.504) and evaporated in vacuo to give a yellow oil. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (4R)-3-(tert-butyloxycarbonyl)thiazolidine-4-carboxamide (8.9g, 38.4mmol, 71%). B. (4R)-Thiazolidine-4-carboxamide hydrochloride (4S).-3-(tert-Butyloxycarbonyl)thiazolidine-4-carboxamide (8.6g, 37.1 mmol) was dissolved in 4M HCI/dioxan (5OmL). After lh at room temperature the solvent was evaporated in vacuo to give a white solid identified as (4R)-thiazolidine-4-carboxamide hydrochloride (6.2g, 36.8mmol, 99%). C. (4R)-3-ENa~(tert~Butyloxycarbonyl)~Afo-(9..fluorenylmethyloxycarbanyl)~L.-lysinyl]-thiazolidine-4-carboxamide N~-(tert-Butyloxycarbonyl)-Nm-(9-fluorenylmethyIoxycarbonyl)-L-lysine (5g, 1 0.7mmol) was dissolved in CH,.CI,. (lOOmL). This solution was cooled .to 00C, (4R)-thiazolidine4-carboxamide hydrochloride (1.78g, 11 .7mmol) and PyBOP (6.7g, 12.8mmol) were added, and the pH was adjusted to pH9 with triethylamine. After I 8h at 000 to room temperature the solvent was removed in vecuo and the residue was taken up in ethyl acetate (200mL). The solution was washed with 0.3M KHSO4 (2 x 5OmL), sat. NaHCO3 (2 x 5OmL), water (2 x 5OmL) and brine (1 x 5OmL), dried (Na,.504) and evaporated in vacua to give a yellow oil. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (4R)-3-~Af-(tert-butyloxycarbonyl)-Nm-(9-fluorenyl-methyloxycarbonyl)-L-lysiny~thiazolidine-4-carboxamide (2..8 1g. 4.8mmol, 44%). D. ~ thiazolidine-4-carbonitrile (4R)-3-[N~'-(tert-Butyloxycarbonyl)-m-(9-fluorenylmethyloxycarbonyl)-L-lysinyl]thiazolidine-4-carboxamide (2.7g, 4.7mmol) was dissolved in dry THF (lOOmL). The solution was cooled to 000, triethylamine (1.0g. 1 Ommol) was added followed by the slow addition of trifluoroacetic anhydride (2.Og, 9.Smmol). The pH was adjusted to pH9 with triethylamine. After 30mm the reaction mixture was diluted with ethyl acetate (lOOmL), washed with water (1 x 5OmL) and brine (1 x 5OmL), dried (Na,.S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 60% pet ether, 40% ethyl acetate) to give a colourless oil identified as (4R)-3-~Af~-(tert-butyloxycarbonyl)-IV0-(9-fluorenylmethyl-oxycarbonyl)-L-lysinylJthiazolidine-4-carbonitrile (2.14g, 3.81 mmol, 82%). E. (4R)-3-(N'~-(tert-Butyloxycarbonyl)-L-lysinylJthiazolidine-4-carbonitrile (4R).-3.{AfL.-(tert.-ButyIoxycarbonyI)~A/ID.-(9~fluorenylmethyloxycarbonyl).-L..lysinyl]thiazolidmne.. 4—carbonitrile (1 .9g, 3.4mmol) was dissolved in Ti-IF (4OmL). Diethylamine (1 OmL) was added. After 2h at room temperature the solvent was removed in vacua. The residue was purified by flash chromatography (eluant: 90% chloroform, 7% methanol, 3% triethylamine) to give a colourless oil identified as (4R).-3-fAfL~(ted-butyloxycarbonyl)~L-lysinyl)thiazolidine-4-carbonitrile (863mg, 2.Smmol, 75%). F.. ~ 4-carbonitrile (4R)~3.-(ML.-(tert.-Butyloxycarbonyl)~L.-lysinyl]thiazolidine..4..carbonitrile (100mg, 0.29mmol) was dissolved in CH,.CI,. (2OmL). To this solution at 000 2-pyrazinecarboxylic acid (43mg, 0.3Smmol) and PyBOP (170mg, 0.33mmol) were added and the pH was adjusted to pH9 with triethylamine. After 18 h at O~C to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). The solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (4R)-3-(N~-(tert-butyloxycarbonyl)-Af-(pyrazinyl-2-carbonyl)-L-lysinyl]thiazolidine-4-carbonitrile (112mg, O.2Smmol, 86%). G. (4R)-3-[N -(Pyrazinyl-2-carbonyl)-L-lysinylJthiazolidine-4-carbonitrile trifluoroacetate (4R)-3-[M1-(tert-Butyloxycarbonyl)-/V~-(pyrazinyl-2-carbonyl)-L-lysinyl]thiazolidine-4- carbonitrile (110mg, 0.26mmol) was dissolved in trifluoroacetic acid (5mL). After 1 h at room temperature the solvent was removed in vacua. The residue was purified by preparative hplc (Vydac 018, 5 to 50% 0.1% TFAlacetonitrile into 0.1% TFAlwater over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a colourless oil identified as (4R)-3-{Nm-(pyrazinyl-2-carbonyl)-L-lysinyl]thiazolidine-4-carbonitrile trifluoroacetate (57mg). [M+H]4 = 349.1 EXAMPLE 4 (2S)-1 -[W~-(Pyridyl-3-methyI)-L-glutaminy~pyrro1idine-2-carbonitriIe clihydrochlonde (Formula Removed) A. (2S)-1 -[N-(tert-Butyloxycarbonyl)-O'~-methyl-L-glutamylJpyrrolidine-2-carbonitrile N-(tert-Butyloxycarbonyl)-00'-methyl-L-glutamic acid (1 .Og, 3.B3mmol) was dissolved in • CH2CI,. /DMF (9:1, 2OmL). To this solution at 000 were added 1-hydroxybenzotriazole hydrate (788mg, 5.84mmol), water-soluble carbodiimide (877mg, 4.38mmol), (2S)-pyrrolidine-2-carbonitrile hydrochloride (609mg, 4.6mmol) and tuiethylamine (65mg, 0.6Smmol). After I 8h at 000 to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL), this solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua. The residue was purified by flash chromatography• (eluant: 50% ethyl acetate, 50% pet. ether) to give a brown oil identified as (2S)-1-[N-(tert- butyloxycarbonyl)-002-methyl-L-glutamyl]pyrro[idine-2-carbonitrile (290mg, 0.B6mmol, 22%). B. (2S)-i -[N-(terl-Butyloxycarbonyl)-L-g lutamyljpyrrolidine-2-carbonitrile (23)-I -{N-(te,t-Buty1oxycarbonyJ)-0'~-methyl-L-g lutamylJpyrrolidine-2-carbonitrile (250mg, O.74mmol) was dissolved in dioxan (5mL). IM Lithium hydroxide (1.lmL, 1.lmmol) was added. After 1 h at room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). This solution was washed with I M KHSO4 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua to give a colourless oil identified as (2S)-1-(N-(tei't-butyloxycarbonyl)-L-glutamyl]pyrrolidine-2-carbonitrile (200mg, O.6lmrnol, 83%). C. (2S)-1 .{N'~-(tert..Butyloxycarbonyl)..W0-(pyridyl..3-methyl)..L-glutaminyl]pyrrolidine. 2-carbonitrile (23)-I -[N-(te,t-Butyloxycarbonyl)-L-glutamyljpyrrolidine-2-carbonitrile (30mg, O.O93mmol) was dissolved in CH,.CI,./DMF (9:1, lOmL). To this solution at 00C was added 1-hydroxy-benzotriazole hydrate (21mg, O.ISmmol), water-soluble carbodiimide (21mg, 0.lOSmmol), 3-(aminomethyl)pyridine (11mg, 0.lmmol) and tiiethylamine(2Omg, 0.2mmol). After I 8h at 000 to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). The solution was washed with O.3M KHSO4 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua to give a yellow oil. The residue was purified by flash chromatography (eluant: 5% methano, 97% chloroform) to give a colourless oil identified as (2S~-1 -[PJ~-(tert-butyioxycarbonyl)-M~-(pyridyl-3-methyl)-L-gIutaminylJpyrrolidine-2-carbonitrile (16.6mg, O.O4mmol, 44%). D. (2S)-1 -[N"'-(Pyridyl-3-methyl)-L-glutaminylJpyrrolidine-2-carbonitrile dihydrochloride (2S)—1 -(N~-(te,t..Butyloxycarbonyl)-N~-(pyridyl-3-methyl)-L-gIutaminyl]pyn-olidine-2.. carbonitrile (17mg, 0.O4mmol) was dissolved in 4M HOI/dioxan (5mL). After lh at room temperature the solvent was removed in vacua to give a white solid identified as (23)-I-fAP-(pyridyl-3-methyl)-L-glutaminyl]pyrrolidine-2-carbonitrile dihydrochloride (17mg, 0.O4mmol, 100%). [M+HJ~ 316.2 EXAMPLE 5 I -[tiP-(Pyrazinyl-2-carbonyl)-L-omithinyl]pyrrolidine trifluoroacetate (Formula Removed) A. I -[N"-(Benzyloxycarbonyl)-N~-(tefl-butyl6xycarbonyI)-L-ornithinylJpyrrolidine iV'~-(Benzyloxycarbonyl)-Af~-(tei~-butyloxycarbonyl)-L-ornithine (5.49g, 1 Smmol) was dissolved in CH,.CI,. /DMF (9:1, 1 OOmL). To this solution at 0~O was added 1-hydroxybenzotriazole hydrate (3.37g, 22mmol), water-soluble carbodiimide (3.46g, l8mmol), pyrrolidine (1.28g. l8mmol) and triethylamine (200mg, 2Ommol). After 18h at 000 to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (200mL). The solution was washed with 0.3M KHSO4 (2 x SGmL), sat. NaHCO3 (2 x 5OmL), water (2 x 5OmL) and brine (1 x 5OmL), dried (Na,.S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 90% ethyl acetate, 10% pet. ether) to give a colourless oil identified as 1-fAf~-(benzyloxycarbonyl)~NcL~(tert~butyloxycarbonyl).-L~ornithinylJpyrrolidine (5.1 5g, I 2.3mmol, 82%). 6.1 -[W-(tert-Butyloxycarbonyl)-L-omithinyl]pyrrolidine I -ENm-(Benzyloxycarbonyl)-N~-(tert-butyloxycarbonyl)-L-omithinylJpyrrolidine (2.1 5g, 5.1 3mmol) was dissolved in methanol (BOmL). This solution was hydrogenated over 10% Pd/C (400mg). After 2h the catalyst was filtered off and washed with methanol (SGmL). The combined.fiitrates were evaporated in vacua to give an off white solid identified as 1- EN'1-(te,t-butyloxycarbonyl)-L-ornithinyUpyrrolidine (I .35g, 4.74mmol, 94%). C. I -[N~-(tert-Butyloxycarbonyl)-IV-(pyraziny1-2-carbonyl)-L-ornithinyl]pyrrolidine I -pV1-(tert-Butyloxycarbonyl)-L-omithinyupyrrolidine (100mg, 0.3Smmol) was dissolved in CH,.CI,. (2omL). To this solution at 00C were added PyBroP (195mg, 0.4mmol), 2- pyrazinecarboxylic acid (50mg, 0.4mmol) and tijethylamine (100mg, 1 .Ommol). After I 8h at 00C to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). The solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHOO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 3% methanol, 97% chloroform) to give a sticky white solid identified as 1.-[Na~(tert~ butyloxycarbonyl)-Af0-(pyrazinyl-2.-carbonyl).-L.-omithiny;Jpyrrolidine (90mg, 0.2Smmol, 66%). D. I -[N"-(Pyrazinyl-2-carbonyl)-L-ornithiny~pyrrondjne trifluoroacetate I ~ (90mg, 0.23mmol) was dissolved in.4M HOI/dioxan (l5mL). After 45mm at room temperature the solvent was removed in vacuo. The residue was purified by preparative hplc (Vydac 018, 5 to 50% 0.1% TFA/acetonitrile into 0.1% TFA/water over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a colourless oil identified as 1-(AP~-(pyrazinyl-2-carbonyl)-L-ommthmnyljpyrrolidine trifluoroacetate (51mg). (Formula Removed) EXAMPLE 6 3-[Nm-(Pyrazrnyl-2-carbony1).-L~on1itiiiny~thiazolidine trifluoroacetate (Formula Removed) ornithinyl]thiazolidine was dissolved in CI-l,.CI,. IDMF (9:1, 1 OOmL). To this solution at 000 were added 1-hydroxybenzotriazole hydrate (1 .53g, 1 Ommol), water-soluble carbodiimide (1 .34g, 7mmol), thiazolidine (1 .28g, I 8mmol) and triethylamine (80mg, 8mmol). After I 8h at 0~C to~ room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (lOOmL). The solution was washed with 0.3M KHSO4 (2 x 25mL), sat. NaHCO3 (2 x 25mL), water (2 x 25mL) and brine (1 x 25mL), dried (Na,.504) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 75% ethyl acetate, 25% pet. ether) to give a white solid identified as 3~(Na.-(tert-buty1oxycarbonyl)-N'~-(9-fluorenylmethyloxycarbonyl)-L-omithinyl]thiazolidine (2.55g. 4.8Smmol, 81%). B. 3-[N~-(tert-8utyloxycarbonyl)-L-omithinyl]thiazolidine N~-(tert-Butyloxycarbonyl)-Nm-(9-fluorenylmethyloxycarbonyl)-L-ornithiny1Jthiazolidine (1.15g, 2.l3mmol) was dissolved in acetonitrile (2OmL). Diethylamine (5mL) was added. After 90mm at room temperature the solvent was removed in vacua and the residue was purified by flash chromatography (eluant: 90% chloroform, 7% methanol, 3% triethylamine) to give a pale yellow oil identified as 3-[N'~-(tert-butyloxycarbonyl)-L-omithinyl]thiazolidine (530mg, 1 .67mmol, 78%). C. 3-ElV't-(te,1-Butyloxycarbonyl)-Ar-(pyrazinyl-2-carbonyl)-L-omithmnyljthiazolidine 3-[N'~-(te,t-Butyloxycarbonyl)-L-omithinylJthiazoIidine (80mg, O.27mmol) was dissolved in CH,.CI,. (2OmL). To this solution at 00C were added PyBroP'~ (146mg, 0.3mmol), 2-pyrazinecarboxylic acid (37mg, 0.3mmol) and triethylamine (90mg, O.9mmol). After 18h at 00C to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL). The solution was washed with O.3M KH504 (2 x 2OmL), sat NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacuo. The residue was purified by flash chromatography (eluant 3% methanol, 97% chloroform) to give a sticky white solid identified as 3-(AI~-(tert-butyloxycarbonyl>-N-(pyrazinyl-2-carbonyl)-L-omithinyl]thiazolidine (45mg, 0.11 mmol, 41%). D. 3-[N-{PyrazinyI-2-carbony4-L-ornithiny~thiazolidine trifluoroacetate 3-(Af2-(tert-Butyloxycarbonyl)-/'f"-(pyrazinyl-2-carbonyl)-L-omithinyljthiazolidine (4 5mg, 0.1 Immol) was dissolved in 4M HOI/dioxan (lOmL). After 45mm at room temperature the solvent was removed in v~cuo. The residue was purified by preparative hplc (Vydac C18, 5 to 50% 0.1% TFA/acetonitrile into 0.1% TFAlwater over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a colourless oil identified as 3-[Nm-(pyrazinyl-2-carbonyl)-L-om ithinyl]thiazolidine trifluoroacetate (14mg). [M+H]~ = 310.0 EXAMPLE 7 (2S)-i ~[S-(Acetylaminomethy~~L-cysteinyl]pyrrolidine-2-carbonitrile trifluoroacetate (Formula Removed) A. (2S)-1 -[S-(Acetylaminomethyl)-N-(tert-butyloxycarbonyl)-L-cysteinylJpyrrolidine-2-carbonitrile S-(Acetylaminomethyl)-N-(tert-butyloxycarbonyl)-L-cysteine (660mg, 2.26mmol) was dissolved in OH,.Ol,. (3OmL). To this solution at 000 were added (2S)-pyrrolidine-2-carbonitrile hydrochloride (250mg, 1 .B9mmol) and PYBOP (1 .3g, 2.49mmol), and the pH adjusted to pH9 with triethylamine. After 18h at 000 to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (1 5OmL). The solution was washed with 0.3M KHSO4 (2 x 3OmL), sat. NaHCO3 (2 x 3OmL), water (2 x 3OmL) and brine (1 x 3OmL), dried (Na,.S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 75% ethyl acetate, 25% pet. ether) to give a colourless oil identified as (23)-I -[S-(acetylaminomethyl)-N-(tert-butyloxycarbonyO-L-cysteinylj pyrrolidine-2-carbonitrile (650mg, 1 .7Gmmol, 78%). B. (2S)-1 -[S-(Acetylaminomethyl)-L-cysteinyljpyrrolidine-2-carbonitrile trifluoroacetate (2S)-1 -[S-(Acetylaminomethyl)-N~(tert-butyloxycarbonyl)-L-cysteinyl]pyrrolid ine-2- carbonitrile (610mg, 1 .65mmol) was dissolved in trifluoroacetic acid (3OmL). After I h at room temperature the solvent was removed in vacua to give a colourless oil identified as (2S>I -[S-(acetylaminomethyl)-L-cysteinyl]pyrrolidine-2-carbonitrile trifluoroacetate (620mg, 1.61 mmol, 98%). EXAMPLE 8 (2S)-1 -[(2'R)-3'-(Acetylaminomethylthio)-2'-amino-3'-methylbutanoyl]pyrrolidine-2- carbonitrile trifluoroacetate (Formula Removed) A. (2S)-1 -[(2'R)-3'-(Acetylaminomethylthio)-2'-(tefl-butyloxycarbonylamino)-3'-methylbutanoyl]pyrrolidine-2-carbonitrile S-(Acetylaminomethyl)-N-(tert-butyloxycarbonyl)penicilla mine (720mg, 2.2Smmol) was dissolved in CH,.CI,. (3OmL). To this solution at 000 were added (2S)-pyrrolidine-2-carbonitrile hydrochloride (270mg, 2..O4mmol) and PyBOP (1 .3g, 2.4Smmol), and the pH adjusted to pH9 with triethylamine. After 18h at 00C to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (1 5OmL). The solution was washed with O.3M 1(1-ISO4 (2 x 3OmL), sat. NaHCO3 (2 x 3OmL), water (2 x 3OmL) and brine (1 x 3OmL), dried (Na2S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 75% ethyl acetate, 25% pet. ether) to give a colourless oil identified as (23)-I -[(2'R)-3'-(acetylaminomethylthio)-2'-(teit-butyloxycarbonylamino)-3'-methylbutanoyl]pyrrolidine-2-carbonitrile (742mg, 1 .86mmol, 83%). B. (2S)-1 ~[(2'R)..3-(Acetylaminomethylthio)-2'-amino-3'-methylbutanoylIpyrroiidine-2-carbon Etrile trifluoroacetate (2S)-1 ~ butanoy~pyrrolidine-2-carbonitrile (710mg, 1.78mmoI) was dissolved in trifluoroacetic acid (3OmL). After I h at room temperature the solvent was removed in vacua to give a colourless oil identified as (2S)-i ~[(ZR)~3-(acetylaminomethylthio)-2'-amino-3'-rnethyl-butanoylJpyrrolidine-2-carbonitrile trifluoroacetate (560mg, 1 .36mmol, 76%). (Formula Removed) EXAMPLE 9 (2S)-1 -[N~-(2-Chloropyridyl-3-carbonyl)-L-omithinyI] pyrrolidine-2-carbonitrile trifluoroacetate(Formula Removed) A. (2S)-1 -(IiP-(tert-Butyloxycarbonyl)-L-ornithyl)pyrrolidine-2-carbOnitrile (2S)-1 -(N~-(tert-Butyloxycarbonyl)-L-ornithyl)pyrrolidine-2-carbonitrile was prepared by the method described for the lysine derivative in Example 2. B. (2S)-1 -(N~-(tert-Butyloxycarbonyl)-IV"-(2-chloropyridyI-3-carbOflyl)-L-OTflithyI)-pyrrolidine-2-carbonitrile (2S)-1 -(N~-(te,t-Butyloxycarbonyl)-L-omithyl)pyrrolidine-2-carbOnitrile (80mg, 0.2Gmmol) was dissolved in CH2012 (2OmL). To this solution was added 2-chloropyridine-3-carbonyl chloride (55mg, 0.32mmol) and the pH adjusted to pH9 with triethylamine. After I 8h at room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). The solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHOO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na2S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant 95% ethyl acetate, 5% pet. ether) to give a colourless oil identified as (2S)-1 -(Af~-(tert-butyloxycarbonyl)-N-(2-chloropyridyl-3-carbonyl)-L-ornithyi)pyrrolidine-2-carbonitrile (60mg, 0.1 4mmol, 53%). C. (2S)-1 -[AF"-(2-Chloropyridyl-3-carbonyl)-L-omithinyl]pyrrolidifle-2-CarbOflitrile trifluoroacetate (2S)-1 ~ carbonitrile (60mg, 0.l4mmol) was dissolved in trifluoroacetic acid (5mL). After lh at room temperature the solvent was removed in vacua. The residue was purified by (Formula Removed) preparative hplc (Vydac C18, 5 to 50% 0.1% TFA/acetonitrile into 0.1% TFAlwater over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a white solid identified as (23)-I ~ trifluoroacetate (52mg). [M+HJ4 350.1 EXAMPLE 10 I -[N~-(2-Chloropyndyl-3-carbonyl)-L-ornithinyl]pyrrolidine hydrochloride A. I -(M-(lert-Butyloxycarbonyl)-N"'-(2-chloropyridyl-3-carbonyl)-L-ornithyl)-pyrrolidine I -( tert-Butyloxycarbonyl)-L-omithyl)pyrrolidine (20mg, 0.O69mmol) was dissolved in 01-12012 (5mL). To this solution was added 2-chloropyridine-3-carbonyl chloride (14mg, 0.O76mmol) and the pH adjusted to pH9 with triethylamine. After lh at room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL). The solution was washed with O.3M KI-1S04 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na2SO4) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 10% methanol, 90% dichioromethane) to give a colourless oil identified as I -(Ai'~-(tert-butyloxycarbonyl)-Af0-(2-chloropyridyJ-3-carbonyl)-L-omithyl)pyrrolidine (19mg, 0.O4Smmol, 63%). B. I ~ hydrochloride 1 -PV'~-(te,t-Butyloxycarbonyl)-M'-(2-chloropyridyl-3-carbonyl)-L-omithinyl]pyrrolidine (19mg, 0.O4SmmoI) was dissolved in 4M HOI/dioxan (lOmL). After 45mm at room' temperature the solvent was removed in vacua to give a white solid identified as 1-(N~-(2-chloropyridyl- 3-carbonyl)-L-omithinyljpyrrolidine hydrochloride (15mg): (Formula Removed) [M+H]~ = 325.1 EXAMPLE 11 ~ hydrochloride A. ~ ithyl)thiazolidine ~ (136mg, 0.45mmol) was dissolved in 0H2C12 (1 OmL). To this solution was added 2-chloropyridine-3-carbOnyl chloride (88mg, Q.5mmol) and the pH adjusted to pH9 with triethylamine. After lh at room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL). The solution was washed with O.3M KHSO4 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na2SO4) and evaporated in vacuo. The residue was purified by flash chromatography (eluant: 1.5% methanol, 98.5% dichloromethane) to give a colourless oil identified as ~ L-ornithyl)thiazolidine (30mg, 0.O68mmoI, 15%). B. ~ iazolid me hydrochloride ~ jazolidine (30mg, 0.O68mmol) was dissolved in 4M HOI/dioxan (lOmL). After 45mm at room temperature the solvent was removed in vacuo to give a white solid identified as 1-(N~-(2-chloropyridyl..3~carbonyl)~L~Orflithinyl]thiaZOlidine hydrochloride (25mg). [M+H]~ = 342.1 EXAMPLE 12 (2S)-1 -[S-(3-Picolylcarbamoylmethyl)-L-cysteinyl]pyrrolidmne-2-carbonitrile trifluoroacetate(Formula Removed) A. S-(Benzyloxycarbonylmethyl)-N-(tert-butyloxycarbonyl)-L-cysteine N-(tert-Butyloxycarbonyl)-L-cysteine (3.5g, I 5.Bmmol), benzyl 2-bromoacetate (3Jg, 16.1 mmcl) and triethylamine (1 .Bg, I 8.Ommol) were dissolved in THF (1 OOmL). After 18 hours at room temperature the reaction mixture was diluted with ethyl acetate (lOOmL), washed with O.3M KHSO4, sat NaHCO3, water and brine, dried (Na2SO4) and evaporated. The residue was purified by flash chromatography (eluant 95% chloroform, 4% methanol, 1% acetic acid) yielding a colourless oil identified as S-(benzyloxycarbonylmethyl)—N-(te,tbutyloxycarbonyl)-L-cysteine (5.2g, 14.1 mmol, 89%). B. (2S)-1 -[S-(Benzyloxycarbonylmethyl)—N-(tefl-butyloxycarbonyl)-L-cystemnyl]pyrrolidine-2-carbonitrlle S-(Benzyloxycarbonylmethyl)---N-(tert-butyloxycarbonyl)-L-cystemne (5.1 Og, I 3.8mmol) was dissolved in CH2012 (200mL). This solution was cooled to 000, (2S)-pyrrolidine-2-carbonitrile hydrochloride (2.lg, 15.Bmmol) and PyBOP (8.Og, 15.Smmol) were added, and the pH was adjusted to pH9 with triethylamine. After I 8h at 0~C to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (l5OmL). This solution was washed with O.3M 1(1-ISO4 (1 x 5OmL), sat. NaHOO3 (1 x 5OmL), water (1 x 5OmL) and brine (1 x 5OmL), dried (Na2S04) and evaporated in vacua to give a yellow oil. This was purified by flash.chromatography (eluant: 40% ethyl acetate, 60% pet. ether) to give a colourless oil identified as (2S)-1-[S-(benzyloxycarbonylmethyl)—N-(tert-butyloxycarbonyl)-L-cysteinyl]pyrrolidmne-2-carbonitrile (5.82g, I 3.Ommol, 94%). C. (2S)-I ~ carbonitrile (2S)-1 ~~S~(Benzyloxycarbonylmethyl)—N-(tert-butyloxycarbOnyl)-L-cysteinyl]pyrrOlidmne-2- carbonitrile (1.31g. 2.9mmol) was dissolved in THF(1 OOmL). Aqueous lithium hydroxide (1 M, 3.5mL, 3.Smmol) was added. After 3 hours at room temperature the reaction mixture was diluted with ethyl acetate (1 OOmL), washed with I M citric acid, water and brine, dried (Na2SO4) and evaporated in vacua to give a colourless oil. This was purified by flash chromatography (eluant: 97% chloroform, 2% methanol, 1% acetic acid) to give a colourless oil identified as (2S)-1 -(N-(tert-butyloxycarbonyl)-S-(carboxymethyD—Lcystemnyl]pyrrolidmne-2-carbonitrile (860mg, 2.4mmol, 82%). 0. (2S)-I - [N~(tert~Butyloxycarbonyl)~S~(3-picolylCarbamoylmethyl)-L-cy5teinylJ-pyrrolidmne-2-carbonitrile (2S)-1 ~[N~(tert~Butyloxycarbonyl)-S-(carboxymethyI)—L-cysteinyl]pyJTOlidine-2-carbonitrile (150mg, O.42mmol) was dissolved in 0H2C12 (2OmL). This solution was cooled to 000, 3~ (ammnomethyl)pyridine (53mg, O.Smmol) and PyBOP (270mg, O.52mmol) were added, and the pH adjusted to pH9 with triethylamine. After 18h at 000 to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). This solution was washed with O.3M KHSO4 (1 x 2OmL), sat Nal-1003 (1 x 2OmL), water (1 x 2OmL) and brine (1 x 2OmL), dried (Na2S04) and evaporated in vacua to give a yellow oil. This was purified by flash chromatography (eluant 96% chloroform, 4% methanol) to give a colourless oil identified as (2S)-1-EN-(ted-butyloxycarbonyl)-S-(3-picolylcarbamoylrnethyl)~L-cysteinyUpyrrolidine-2-carbOnitrile (170mg, 0.3Bmmol, 91%). E. (2S)-1 ~[S~(3-PicoIylcarbamoylmethyl)-L-cystemnyl]pyrrOlidifle-2-carbOnitFile trifluoroacetate (2S)-1 ~ carbonitrile (130mg, 0.29mmol) was dissolved in trifluoroacetic acid (1 OmL). After 1 hour at room temperature the solvent was removed in vacua to give a white solid identified as (2S)-1 ~ trifluoroacetate (11 6mg,0.2Smmol, 86%). (M+Hjt = 348.2 EXAMPLE 13 3-fN~-(2-QuinoxaloyI)-L-lysinyl]thiazolidine hydrochloride (Formula Removed) 3-[M1-(tert-Butyloxycarbony~lysinyl]thiazolidine (128mg, 0.4mmol) was dissolved in CH2CI2 (1 OmL). 2-Quinoxaloyl chloride (85mg, O.44mmol) and potassium carbonate (45.8mg, O.3mmol) were added. The reaction mixture was stirred at room temperature for 18 hours and the solvent removed in vacuo. The residue was purified by flash chromatography (eluant 99.5% chloroform, 0.5% methanol) to give a colourless oil identified as 3-[tf-(fert-butyloxycarbonyl)-Af0-(2-quinoxaloyl)-L-lysinyl]thiazolidine (140mg, 0.29Gmmol, 74%). B. 3-[Ar~-(2-Quinoxaloyl)-L-lysinyl]thiazolidine hydrochloride 3-[AP-(telt-Butyloxycarbonyl)-Nm-(2-quinoxaloyl)-L-lysinylJthiazolidine (140mg, 0.296mmo1) was dissolved in 4M HOI/dioxan (2OmL).. After 1 hour at room temperature the solvent was removed in vacuo to give a white solid identified as ~ lysinylJthiazolicline hydrochloride (128mg, 0.296mmo1, 100%). [M+H]~ = 374.2 (Formula Removed) EXAMPLE 14 3-[W"-(3-Pyridyloxycarbonyl)-L-omithinyl]thiazolidine hydrochloride A. 3-[W-(tert-Butyloxycarbonyl)-N8-(3-pyridyloxycarbonyl)-L-omithinyl]thiazolidine 3-Hydroxypyridine (14.9mg, 0.l38mmol) was dissolved in 0H2C6 (2OmL). Phosgene (20% solution in toluene, 0~335mL, O.6BSmmol) and pyridine (14mg, 0.lB2mmol) were added at 000. After 90 mins the solvent was removed in vacuo and the residue dissolved in CH2CI2 (2OmL). 3-[Nm-(tert-Butyloxycarbonyl)ornithinyl]thiazolidine (42mg, 0.1 38mmol) and triethylamine (28mg, 0.28mmol) were added. The reaction mixture was stirred at room temperature for 18 hours and the solvent removed in vacuo. The residue was purified by flash chromatography (eluant: 970/o chloroform, 3% methanol) to .give a colourless oil identified as 3-(AC-(tet-butyloxycarbonyl)-N-(3-pyridyloxycarbonyl)-L-ornithinyl]thiazolidine (16mg, 0.O38mmol, 27%). B.. 3-[It-(3-Pyridyloxycarbonyl)-L-omithinyljthiazolidine hydrochloride 3-fM~-(te,t-Butyloxycarbonyl)-N~-(3-pyriclyloxycarbonyl)-L-omithiny~thiazolidine (16mg, 0.O38mmol) was dissolved in 4M HOl/dioxan (2OmL). After 1 hour at room temperature the solvent was removed in vacuo to give a white solid identified as 3-[M"-(3-pyridyloxycarbonyl)-L-omithinyl]thiazolidine hydrochloride (14mg, 0.O38mmol, 100%). (Formula Removed) EXAMPLE 15 3-[O-(3-Chlorobenzylcarbamoyl)seriny~thiazolidine hydrochloride A. 3-[N-(tert-Butyloxycarbonyl)—L-serinyljthiazolidine N-(teit-Butyloxycarbonyl)-L-serine (2.1 g, I 0.2mmol) was dissolved in CH2CI2IDMF (9:1 ,5OmL). Thiazolidine (650mg, 11 .2mmol), hydroxybenzotriazole(2.8g, 20.7mmol) and water soluble carbodiimide (3.9g, 19.Smmol) were added at 00C. The pH was adjusted to pH8 with N-methylmorpholine. The reaction mixture was stirred at room temperature for 18 hours, the solvent removed in vacuo and the residue was taken up in ethyl acetate (1 5OmL). This solution was washed with 0.3M 1(1-ISO4 (1 x 5OrnL), sat NaHCO3 (1 x 5OmL), water (1 x 5OmL) and brine (1 x 5OmL), dried (Na2SO4) and evaporated in vacuo to give a white solid identified as 3-(N-(teft-butyloxycarbonyl)-L-serinyUthiazolidine (2.15g, 7.7Bmmol, 76%). B. 3-[N-(iert-Butyloxycarbonyl)—O-(3-chlorobenzylcarbamoyl)-L-serinyl]thiazolidine 3-[N-(tert-Butyloxycarbonyl)-L-serinyl]thiazolidine (110mg, 0.4Bmmol) was dissolved in DMF (lOmL) and 1,1'-carbonyl-diimidazole (71mg, 0.43mmol) was added. After 2 hours at room temperature 3-chlorobenzylamine (62mg, 0.4mmol) was added. After a further 18 hours EtOAc (200mL) was added. This solution was washed with 0.3M 1(1-ISO4 (1 x 5OmL), sat. NaHOO3 (1 x 5OmL), water (4 x 5OmL) and brine (1 x 5OmL), dried (Na2S04) and evaporated in vacuo to give a yellow oil. This was purified by flash chromatography (eluant 40% ethyl acetate, 60% pet. ether) to give a colourless oil identified as 3-(N-(tert-butyloxycarbonyl)-O-(3-chlorobenzylcarbamoyl)-L-serinyl]thiazolidine (158mg, 0.36mmol, 90%). C. 3-[O-(3-Chlorobenzylcarbamoyl)-L-sennyl]thiazolidine hydrochloride 3-[N-(te,t-Butyloxycarbonyl)-O-(S-chlorobenzylcarbamoyl)-L-sennyljthiazolidine (140mg, 0.32mmol) was dissolved in 4M HOI/dioxan (2OmL). After 1 hour at room temperature the solvent was removed in vacuo to give a white solid identified as 3-[O-(3-chlorobenzylcarbamoyl)-L-serinyl]thiazolidine hydrochionde (115mg, 0.3mmol, 94%). tM+H1~ = 344.1 The Examples set out in the following Tables were prepared by analogous methods to the above. TABLE I — Examples 16— 162 (Table Removed) TABLE 2— Examples 163 —250 (Table Removed) TABLE 3— Examples 251 — 266 (Table Removed) TABLE 4— Examples 267 — 318 (Table Removed) TABLE 5— Examples 319 — 378 (Table Removed) TABLE 6— Examples 379 —418 (Table Removed) TABLE 7— Examples 419 — 438 (Table Removed) TABLE 8— Examples 439 — 450 (Table Removed) EXAMPLE 451 Determination of activity Oompounds were assayed as inhibitors of DP-IV according to the methods described in W095/1 5309. All the compounds described in the foregoing Examples were competitive inhibitors of DP-IV with 1'~ values less than 300nM. EXAMPLE 452 Determination of activity in vivo The anti-diabetic action of selected compounds was demonstrated in Zucker obese rats using a standard oral glucose tolerance test. Oontrol rats were given a solution of glucose by oral gavage, and plasma glucose levels were determined. These rats demonstrated a significant hyperglycaemia. Oompounds according to the present invention were dissolved in glucose solution at various concentrations, such that the rats could be given varying doses of the compound simultaneously with the glucose challenge. The hyperglycaeinic excursion was reduced in a dose-dependent manner in animals receiving between 0.1 and 100 mg/kg of DP-IV inhibitor. EXAMPLE 453 Pharmaceutical formulation Tablets containing 100mg of the compound of Example I as the active agent are prepared from the following: Oompound of Example I 200.Og Oorn starch 71.Og Hydroxypropylcellulose 18.Og Oarboxymethylcellulose calcium 13.Og Magnesium stearate 3.Og Lactose 195.Og Total 500. Og The materials are blended and then pressed to give 2000 tablets of 250mg, each containing 100mg of the compound of Example 1. The above demonstrates that the compounds according to the present invention are inhibitors of DP-IV and would accordingly be expected to be useful as therapeutic agents for the treatment of impaired glucose tolerance, type II diabetes, and other diseases where inhibition of this enzyme leads to an improvement in the underlying pathology or the symptoms. We claim: A compound selected from derivatives of formula I that are inhibitors of the enzyme of dipeptidyl peptidase IV, its tautomers and stereoisomers thereof, and pharmaceutically acceptable salts of said derivatives, tautomers and isomers (Formula Removed) wherein: X' is selected from a sulphur atom, an oxygen atom, a sulphinyl group, a sulphonyl group and a methylene group; X2 is methylene; X3 is either a carbonyl or thiocarbonyl group; R1 is either a hydrogen atom or a nitrile group; R2 and R3 are independently selected from K and C1-C6 alkyl, or together may be -(CH2)p.; R4 is R6 R7 N; R' and R7 are selected independently from R8(CH2)q or together they are(CHz)2-Z'- (C1-C2)- or -CHR9 -Z2CHz-CI-tR'0-; R8 is selected from H, C1-C6 alkyl, benzo- fused cyclo (C1-C6)alkyl, (C1-C6) alkyl-to acyl, di (C1-C6) alkylamino, N- (C1-C6)alkylpiperidyl, substituted aryl, optionally substituted alkylbenzyl, optionally substituted aroyl, and optionally substituted arylsulphonyl R9 and R'0 are selected independently from H, carbamoyl, hydroxymethyl and cyanomethyl; Z' Is selected from a covalent bond, -(CHz)r-, -o-, -sot- and - N((CHz)qR8) (Formula Removed) Z2 is an optionally substituted ortho-phenylene moiety; m is 1 - 3; n is 0 - 4; p is 2 - 5; q is 0 - 3; r is I or 2; and tisO-2; the optional substitutent(s), if present, being selected from (C1-C6) alkyl, aryl which may be further substituted with one or more methyl or trifluoromethyl groups, hydroxy, (C1-C6) alkyloxky, (C1-C6)alkylsulphonyl, acyl, perfluroacyl, amino, (C1-C6) alkylamino, di(C1-C6)alkyl amino, amino alkylene, fluoro, chloro, bromo,trifluoromethyl, nitro, cyano, carbamoyl, carboxy and (C1-C6) alkyloxycarbonyl group and/or where two adjacent substituents are present, the two adjacent substituents may be linked so as to form a ring fused to the parent aryl or heteroaryl ring. 2. A compound as claimed in claim 1 wherein R1 is a nitrile group. 3. A compound as claimed in claim 2 wherein the stereocherrnstry of the nitrile group is as shown in formula 2. (Formula Removed) 4. A compound as claimed in claim I or or 2 wherein the stereochemistry of the centre adjacent to the primary amine is of the S configuration as shown in formula 3. (Formula Removed) 5. A compound as claimed in claim 4 wherein R' is a nitrile group and the stereochemistry of the nitrile group is as shown in formula 4. (Formula Removed) 6. A compound as claimed in any preceding claim wherein m is 1. 7. A compound as claimed in any preceding claim wherein R2 and R3 are independently H or methyl. 8. A compound as claimed in any preceding Claim wherein m is 1 and R2 and R3 are both H. 9. A compound as claimed in any of Claims 1 to 7 wherein m is 1, 112 and R~ are both H, n is 0 and X3 is CO. 10. A compound as claimed in claim 9 wherein R4 is R6NH. 11. A compound as claimed in claim 1 wherein R' is H and X' is S. 12. The pharmaceutical composition for the treatment of at least one of type 2 diabetes, impaired glucose tolerance, growth hormone deficiency, polycystic ovary syndrome, and auto- immune and inflammatory diseases, the composition comprising at least one compound which is selected from derivatives of formula A, tautomers and stereolsomers thereof, and pharmaceutically acceptable salts of said derivatives, tautomers and isomers, or which is as claimed in any of claims 1 to 11

Full Text

Field Of Invention
The present invention relaters to a compound selected from derivatives of

formula 1 that are inhibitors of the enzyme of dipeptidyl peptidase IV.
Background
The enzyme dipeptidyl peptidase IV, herein abbreviated DP-IV (and elsewhere as DAP-IV or DPP-IV) and also known by the classification EC.3. 4.14.5, is a serine protease that cleaves the N-terminal dipeptide from peptides that begin with the sequence H-Xaa-Pro (where Xaa is any amino acid, although preferably a lipophilic one, and Pro is proline). It will also accept as substrates peptides that begin with the sequence H-Xaa-Ala (where Ala is alanine). DP-IV was first identified as a membrane-bound protein. More recently a soluble form has been identified.
Initial interest in DP-iV focussed on its role in the activation of T lymphocytes. DP-IV is identical to the T cell protein CD26. It was proposed that inhibitorsof DP-IV would be capable of modulating T cell responsiveness, and so could be developed as novel immunomodulators. It was further suggested that CD26 was a necessary co-receptor for HIV, and thus that DP-IV inhibitors could be useful in the treatment of AIDS.
Attention was given to the role of DP-IV outside the immune system. It was recognised that DP-IV has a key role in the degradation of several peptide hormones, including growth hormone releasing hormone (GHRH) and glucagonlike peptide-1 and -2 (GLP-1 and GLP-2). Since GLP-1 is known to have a potentiating effect on the action of insulin in the control of post-prandial blood glucose levels it is clear that DP-IV inhibitors might also be usefully employed in the treatment of type 11 diabetes and impaired glucose tolerance. At least two DP-IV inhibitors are currently undergoing clinical trials to explore this possibility.

Several groups have disclosed inhibitors of DP-IV. While some leads have been found from random screening programs, the majority of the work in this field has been directed towards the investigation of substrate analogs. Inhibitors of DP-IV that are substrate analogs are disclosed in, for example, US 5,462,928, US 5,543,396, WO 95/15309 (equivalent to US 5,939,560 and EP 0731789), WO 98/19998 (equivalent to US 6,011,155),
W099/46272 and .W099/61431. The most potent inhibitors are aminoacyf pyrrolidine boronic acids, but these are unstable and tend to cyclise, while the more stable pyrrolidine and thiazolidine derivatives have a lower affinity for the enzyme and so would require large doses in a clinical situation. Pyrrolidine nitriles appear to offer a good compromise since they have both a high affinity for the enzyme and a reasonably long half-life in solution as the free base. -There remains, however, a need for inhibitors of DP-IV with improved properties.
Brief Description of the Invention
The present invention relates to a series of inhibitors of DP-IV with improved affinity for the enzyme. The compounds can be used for the treatment of a number of human diseases, including impaired glucose tolerance and type II diabetes. Accordingly, the invention further relates to the use of the compounds in the preparation of pharmaceutical compositions, to such compositions per Se, and to the use of such compositions in human therapy. The compounds of the invention are described by general formula 1.

(Formula Removed)

ln general formula I, X' is selected from —S-., -0.-, -SO-, -SOT and —CHT; X2 is selected from —0-, -5-, -NH- and —CHT; X3 is either -NR5- or a >00 or >0=5 group; R' is either H or -ON; R2 and R3 are independently selected from H and lower alkyl, or together may be
-(CH2)~-; R4 is R4A when X3 is -NR5- and R4B when X3 is >0=0 or >C=S; R~ is selected from R6R7NC(=O), R6RTNC(=S); R8(CH2)qC(=O), R8(CH2)qC(5), R8(0H2)qSO2, R8(CH2)qOC(5) and R8(0H2)qOC(=O); R4B is R6R7N; R5 is H or lower alkyl; R8 and R7 are each independently R8(0H2)q or together they are —(0H2)TZ-(0H2)T; R8 is selected from H, alkyl, optionally substituted aryl, optionally substituted aroyl, optionally substituted arylsulphonyl and optionally substituted heteroaryl; Z is selected from a covalent bond, ~~; n is 0—4; p is 2—5; q is 0—3; r is I or 2; and t is 0
Detailed Description of the Invention

In a first aspect, the present invention comprises a series 6f novel compounds. that are inhibitors of the enzyme DP-IV and are useful for the treatment of certain human diseases. The compounds are described by general formula I.

(Formula Removed)
In general formula I, X1 is a divalent group selected from a sulphur atom (—5-), an oxygen atom (-0-), a suiphinyl group (-SO-), a suiphonyl group (-SOT) and a methylene group (-OH,.-). X2 is a divalent group selected from an oxygen atom (—0-), a sulphur atom (-5-) and a methylene group (—OH,.-). X3 is either a substituted imino group (-NR5-) or a carbonyl (>0=0) or thiocarbonyl (>0=5) group.

R' is either a hydrogen atom (H) or a nitrile group (-ON).

R2 and R3 may each independently of the other be a hydrogen atom or a lower alkyl group, or together they may be a chain of between two and five methylene units (-(OH,.)~- where p is in the range 2 — 5) so as to form, with the carbon atom to which they are attached, a three,-four, five or six-membered ring. The value of m may be 1, 2 or 3. When m is greater than I then each 0R2R3 unit may be the same or different. For example, when m is 2 then (0R2R3),. may be OH,.OH,., OH,.O(Me),., O(Me),.OH,. and the like.

The nature of R4 depends on the identity of X3, such that the two groups are linked by an amide (CO-N), thioamide (05-N) or sulphonamide (SO,..-N) bond. So, when X8 is a substituted imino group (-NR5-) then R4 is ~ where R4A is selected from carbamoyl groups (R6R7NC(=O)), thiocarbamoyl groups (R6R7NO(=S)); optionally modified acyl groups (RNOI~l~)qO(=O)), optionally modified thioacyl groups (R8(CH2)qOQ~S)), sulphonyl
groups (R8(CHz)qSO2), optionally modified (alkyl or aryloxy)carbonyl groups (R8(CH2)qOO(0)) and optionally modified (alkyl or aryloxy)thiocarbonyl groups(R8(CH,.)qOC(=S)). As used herein, the tern, "optionally modified" is taken to indicate that some embodiments of R8 are beyond the scope of the terms '~alkyl~, "acyr and "aryl". The scope of the definition of R'~ is determined by the scope of the definition of RB. Alternatively, when X3 is a carbonyl (>0=0) or thiocarbonyl (>C~S) group then R4 is R48, where R4B is a substituted amino group (R8R7N).
R5 is a hydrogen atom (H) or a tower alkyl group. Preferably, R5 is H.
R8 and R7 may each independently of the other be R8(CH2)q. Alternatively, they may together be a group —(OH,.),.-Z1-(CH,.),.- or —CHR9-Z2-CH,.--OR'0-. Here Z' is a covalent bond, a methylene or ethylidene group (-(OH~- where r is I or 2), an oxygen atom (-0-), a sulphur or oxidised sulphur atom (-SOr where t is zero, I or 2) or a substituted imino group (~N((CH2)qR8)), such that the group NR6R7 is a pyrrolidine, piperidine, perhydroazepine, morpholine, optionally oxidised thiomorpholine or substituted piperazine ring. Z2 is an ortho-phenylene moiety (—C6H4--), such that the group NR6R7 is a tetrahydroisoquinoline.

R8 is selected from a hydrogen atom (H), a lower alkyl group, a benzo-fused lower cycloalkyl group (such as an indanyl group), an acyl (lower alkyl-CO) group, a di(lower alkyl)amino group, a di(lower alkyl)carbamoyl group, an N-(lower aIkyl)piperidinyl group, an optionally substitiued a-alkylbenzyl group, an optionally substituted phenyl, naphthyl or heteroaryl group, and an optionally substituted aroyl (aryl-CO) or arylsulphonyl (aryl-S02) group. In the foregoing, suitable optional substituents are lower alkyl, aryl which may be further substituted with one or more methyl or trifluoromethyl groups, hydroxy, lower alkyloxy, lower alkylsulphonyl, acyl, perfiuoroacyl, amino, lower alkylamino, di(lower alkyl)amino, aminoalkylene, fluoro, chloro, bromo, trifluoromethyl, nitro, cyano, carbamoyl, carboxy and lower aikyloxycarbonyl groups. In addition, two adjacent substituents may be linked so as to form a ring fused to the parent aryl or heteroaryl ring.

R9 and R10 are independently selected from hydrogen, carbamoyl, hydroxymethyl and cyanomethyl groups.
The integer n is selected from the range zero to 4, and q is selected from the range zero to
3.
Certain compounds are specifically excluded from the scope of the present invention. When X2 is methylene, X3 is NH and R4 is R8(CHz)qO(CO), with q = , then R8 may not be unsubstituted phenyl or phenyl substituted with a nitro group. It is generally preferred that when X2 is methylene, X3 is NH, R4 is R8(CH2)qQ(OO), q is I and RB is a substituted phenyl group then the substituent or substituents should be selected from chloro, methoxy and trifluoromethyl groups.

In the context of the present disclosure, the term lower alkyl, either by itself or in such combinations as lower alkyloxy, is intended to comprise linear, branched and cyclic saturated hydrocarbon groups of between one and six carbon atoms. Examples of lower alkyl groups include, but are not limited to, methyl, ethyl, isopropyl, tert-butyl, neopentyl, cyclohexyl, cyclopentylmethyl, 2-(cyclopropyl)ethyl, 3,3-dimethylcyclobutyl and bicyclo[3. 1 .Ojhexyl.

The term heteroaryl includes monocyclic five- and six-membered ring aromatic groups with one or two heteroatoms, which are selected from nitrogen, oxygen and sulphur. Thus, heteroaryl groups include pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, pyrrolyl, thienyl, furyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl and isoxazolyl. Heteroaryl further includes the benzofused derivatives of these rings, such as quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, phthalazinyl, cinnolinyt, indolyl, isoindofyf, benzothiazolyl and the like, and bicyclic groups formed by the fusion of two such monocyclic heteroaromatic groups.

The term aryl includes phenyl, naphthyl and heteroaryl.

The compounds of general formula I have at least one stereogenic centre and so can exhibit optical isomerism. All such isomers, including enantiomers, diastereomers and epimers are included within the scope of the invention. Furthermore, the invention includes such compounds as single isomers and as ~mixtures, including racemates. Certain compounds according to general formula, including those with a heteroaryl group which carries a hydroxy or amino substituent, can exist as tautomers. These tautomers, either separately or as mixtures, are also considered to be within the scope of the invention.
The compounds according to general formula I have at least one basic functional group. They can therefore form addition salts with acids. Those addition salts that are formed with pharmaceutically acceptable acids are included within 'the scope of the invention. Examples of suitable acids include acetic acid, trifluoroacetic acid, citric acid, fumaric acid, benzoic acid, pamoic acid, methanesulphonic acid, hydrochloric acid, nitric acid, sulphuric acid, phosphoric acid and the like.

Certain compounds according to general formula I have an acidic group and so are able to form salts with bases. Examples of such salts include the sodium, potassium and calcium salts, which are formed by the reaction of the acid with the corresponding metal hydroxide, oxide, carbonate or bicarbonate. Similarly, tetra-alkyl ammonium salts may be formed by the reaction of the acid with a tetra-alkyl ammonium hydroxide. Primary, secondary and tertiary amines, such as triethylamine, can form addition salts with the acid. A particular case of this would be an internal addition salt formed between an acidic group and the primary amine group of the same molecule, which is also called a zwitterion. Insofar as they are pharmaceutically acceptable, all these salts are included within the scope of the invention.

In a preferred embodiment of the invention R1 is a nitrile group. Within this embodiment, it is preferred that the stereochemistry of the nitrile group is as shown in general formula 2.
(Formula Removed)
According to the standard terminology, this is the S configuration when X' is methylene but the R configuration when X1 is sulphur, oxygen, sulphinyl or sulphonyl.

In another preferred embodiment, the stereochemistry at the centre adjacent to the primary amine is as shown in general formula 3. This is the S configuration when X2 is an oxygen atom or a methylene or imino group, and the R configuration when X2 is a sulphur atom.
(Formula Removed)
Within this embodiment, it is more preferred that R1 should be a nitrile group, and more preferred still that it should have the absolute configuration depicted in general formula 4.
(Formula Removed)
In another preferred embodiment of the invention, m is 1. More preferably m is I and R2 and R3 are independently hydrogen atoms or methyl groups. When X2 is a methylene group, it is more preferred that R2 and R3 both be hydrogen. When X2 is an oxygen atom, it is more preferred that one of R2 and R3 be hydrogen and the other a methyl group. When X2 is a sulphur atom, it is more preferred that both R2 and R3 be methyl groups.

In another preferred embodiment, X1 is either S or methylene. More preferably, X1 is S and R' is H, or K1 is methylene and R1 is CN.

In another preferred embodirnent, X3 is NH. More preferably. X3 is NH, m is 1, R2 and R3 are both H, X2 is methylene and n is I or 2.

In another preferred embodiment, R4 is R8NHCO or R800 and R8 is an optionally substituted heteroaryl group. More preferably, R5 is an unsubstituted heteroaryl group, or a heteroaryl group substituted with one or two groups chosen from lower alkyl, lower alkyloxy, fluoro, chioro and trifluoromethyl groups.
In another preferred embodiment, X3 is 00 and R4 is R6NH. More preferably R8 is an optioriaUy substituted heteroaryl' group. More preferably still, R5 is an unsubstituteci heteroaryl group, or a heteroaryl group substituted with one or two groups chosen from lower alkyl, lower alkyloxy, fluoro, chloro and trifluoromethyl groups.

In another preferred embodiment, X3 is NH and R4 is selected from R6R7N(O0), R8(0H2)qCO and R8(CH2)q502.

Particularly preferred compounds within the invention include:

(2S)-l-[AP-(Pyrazinyk2-carbonyl)..L.-ornithinyl]pyrroIidine.-zca~onftgile,

(2S)-1 -[N~-(Pyrazinyl-2-carbonyl)..L.-lysinyI]pyrrolidine..2~carbonjtrile,

(2S)4{(2tS)-21-Amino-4'-(pyrazinyl..V..cabonylamino)butanoylJpyrm1idine-~ca~-~nj.jjfe
(4R)-3-[Nm-(Pyrazinyl-2-carbonyi).-L.-iysinyl]thiazolidine4.carbonitrije,
(2S)-l-IAP-(Pyridyl-3-methy~-L.-glutaminy~pyrrolicune.-2~carbot,itrife,

I -[N~-(Pyrazinyl-2-carbonyl)-L-omithinyl]pyrrolidine,

(2S)-1 -[S-(Acetylaminomethyl)..L-cysteinyl]pyrroliciine..2~carbonitriIe,

3-ENm-(2-Ohloropyridyl-3-carbonyl).-L-omithinyqthiazolidine,
I ~ and
3-1N0-(Pyrazinyl-2-carbonyl)-L.-ornithinyljthiazolidine,

3-[IV'0-(2-Quinoxaloyl~L.-lysinyl]thiazolidine
3-~N"'-(2-QuinoxaIoyI)-L-omithinyl]thiazolidine~

(25)-I -(N~-(2-Quinoxaloyl)-L-ornithinylJpyrroJidine-2-carbonitrile,

3..fN"..(6..Methylpyrazinyl-2..carbonyl)..L..ornithinyl]thiazolidine,

3-[i%f~-(lsoquinoline-3-carbonyl).-L-.omithinyl]thiazolidine,
3-[Af-(B-Trifluoromethylnicotinoyl)4...omithinyl]thiazolidine,
(2S)-I -[(2'R)-3'-(Acetylaminomethylthio)-2-amino-3'-methylbutanoyl]pyrrolidine-2.. carbonitrile,
(2S)-I -[S-(3-Piolylcarbamoylmethyl>.L-cysteinyl]pyrrolidine-2-carbonitrile,

3-{Ar-(3-Pyridyloxycarbonyl)-L-omithinyrjthiazolidine,

3-[O-(3-Chlorobenzylcarbamoyl)seiinyl]thiazolidine, and
3.{(2'S).2'..Amino-5'..oxo..5'..{I ",2",3" ,4"-tetrahydroisoquinolin-2"-yl)pentanoyl]thiazolidine.
In a second aspect, the present invention comprises a pharmaceutical composition for human therapeutic use. The composition is charactetised in that it has, as an active agent, at least one of the compounds described above. Such a composition is useful in the treatment of human diseases. The composition will generally include one or more additional components selected from pharmaceutically acceptable excipients and pharmaceutically active agents other than those of the present invention.

The composition may be presented as a solid or liquid formulation, depending on the intended route of administration. Examples of solid formulations include pills, tablets, capsules and powders for oral administration, suppositories for rectal or vaginal .administration, powders for nasal or pulmonary administration, and patches for transdermal or transmucosal (such as buccal) administration. Examples of liquid formulations include solutions and suspensions for intravenous, subcutaneous or intramuscular injection and oral, nasal or pulmonary administration. A particularly
preferred presentation is a tablet for oral administration. Another preferred presentation, particularly for emergency and critical care, is a sterile solution for intravenous injection.

The composition comprises at least one compound according to the preceding description. The composition may contain more than one such compound, but in general it is preferred that it should comprise only one. The amount of the compound used in the composition will be such that the total daily dose of the active agent can be administered in one to four convenient dose units. For example, the composition can be a tablet containing an amount of compound equal to the total daily dose necessary, said tablet to be taken once per day. Alternatively, the tablet can contain half (or one third, or one quarter) of the daily dose, to be taken twice (or three or four times) per day. Such a tablet can also be scored to facilitate divided dosing, so that, for example, a tablet comprising a full daily dose can be broken into half and administered in two portions. Preferably, a tablet or other unit dosage form will contain between 0.1mg and Ig of active compound. More preferably, it will contain between 1mg and 250mg.

The composition will generally include one or more excipients selected from those that are recognised as being pharmaceutically acceptable. Suitable excipients include, but are not limited to, bulking agents, binding agents, diluents, solvents, preservatives and flavouring agents. Agents that modify the release characteristics of the composition, such as polymers that selectively dissolve in the intestine ("enteric coatings") are also considered in the context of the present invention, to be suitable excipients.

The composition may comprise, in addition to the compound of the invention, a second pharmaceutically active agent. For example, the composition may include an anti-diabetic agent, a growth-promoting agent, an anti-inflammatory agent or an antiviral agent However, it is generally preferred that the composition comprise only one active agent

In a third aspect, the invention comprises a use for the compounds and compositions described above for the treatment of human diseases. This aspect can equally be considered to comprise a method of treatment for such, diseases. The diseases susceptible to treatment are those wherein an inhibition of DP-IV or CD26 results in a clinical benefit either directly or indirectly. Direct effects include the blockade of T lymphocyte activation. indirect effects include the potentiation of peptide hormone activity by preventing the degradation of these hormones. Examples of diseases include, but are

(Formula Removed)
not limited to, auto-immune and inflammatory diseases such as inflammatory bowel disease and rheumatoid arthritis, growth hormone deficiency leading to short stature, polycystic ovary syndrome, impaired glucose tolerance and type 2 diabetes. Particularly preferred is the use of the compounds and compositions for the treatment of impaired glucose tolerance and type 2 diabetes, and equally a method of treatment of these diseases by the administration of an effective amount of a compound or composition as previously described.

The precise details of the treatment, including the dosing regimen, will be established by the attending physician taking into account the general profile of the patient and the severity of the disease. For diseases such as inflammatory bowel disease that have acute phases of active disease separated by quiescent periods, the physician may select a relatively high dose during the acute phase and a tower maintenance dose for the quiescent period. For chronic diseases such as type 2 diabetes and impaired glucose tolerance, the dosing may need to be maintained at the same level for an extended period. A dosing schedule of one to four tablets per day, each comprising between 0.1mg and Ig (and preferably between 1mg and 250mg) of active compound might be typical in such a case.

The compounds according to the invention can be prepared by methods known in the art. The route chosen will depend on the particular nature of the substituents present in the target molecule. In the following general description the synthetic route is outlined for compounds wherein m is 1. Compounds with m = 2 or 3 can generally be prepared by analogous routes.

The starting material will usually be an c,co-diamino acid derivative 5 or an amino dicarboxylic acid derivative 6.

(Formula Removed)
PG' and PG2 are "orthogonal" protecting groups — groups that mask the reactivity of the amine groups and that can each be selectively removed in the presence of the other. Suitable groups are well known in the literature. PG3 and PG4 are protecting groups for carboxylic acids. They are chosen such that they are orthogonal to each other and to the amino protecting groups. Suitable possibilities for PG3 and PG4 are also well known in the literature. Derivatives of diamino acids according to general formula 5 and derivatives of amino dicarboxylic acids according to general formula 6 are either items of commerce, or can be prepared following methods described in the literature. In practice, and depending on the strategy chosen, the starting material will have only two of the three protecting groups present. Either PG3 will be absent to allow the pyrrolidine (or thiazolidine or oxazolidine) residue to be introduced, or PG' or PG4 will be absent to allow the side chain to be elaborated.

Scheme A illustrates the introduction of the pyrrolidine (or thiazolidine or oxazolidine) group as the first step in the preparation of the compounds of the invention.

Scheme A (Scheme Removed)
Compounds 5A and 6A correspond to 5 and 6 with PG3 as a hydrogen atom (i.e. without the protecting group). The free carboxylic acid can be reacted with a pyrrolidine derivative 7 to give the amide 8 or 9. Reaction conditions for achieving this transformation are well

(Formula Removed)
known in the literature. Suitable reagents include carbodiimides, phosphorus reagents and alkyl chloroformates, and the reaction is usually catalysed by a tertiary amine such as triethylamine or dimethylaminopyridine.

The reaction depicted in Scheme A is available for all combinations of R1 and K'. However, for the case where R' is a nitnle group, or where K' is a sulphinyl or sulphonyl group, it may be advantageous to modify the strategy as depicted in Schemes B and 0.

Scheme B (Scheme Removed)
ln Scheme B, the R1 group is introduced as a primary amide and subsequently transformed into a nitrile by the action of a dehydrating agent such as trifluoroacetic anhydulde. In Scheme C, the K' group is introduced as a thioether and subsequently transformed into a sulphoxide (a=1) or sulphone (a=2) by the action of an oxidant such as sodium periodate. The modification to the strategy afforded by Scheme C is not possible if X2 is a sulphur atom.

Scheme D (Scheme Removed)

ln Scheme D, compound 5D is the diamino acid derivative 5 where the a-protecting group is a hydrogen atom. The free amine group reacts readily with sulphonyl chlorides, acyl chlorides and thicacyl chlorides, usually in the presence of a tertiary amine. to produce sulphonarnides 14, amides 15 and thicamides 16 respectively. The reagents are generally either available per se, or can be prepared from the corresponding acids. The reaction of scheme D is generally applicable to all the variations of the group R8(CI~l2)q, with the proviso that certain of the substituents contemplated for the phenyl and heteroaryl rings which are options for RB may require, protection. Such substituents and the appropriate protection will generally be obvious to those familiar with the art.
Scheme E (Scheme Removed)

Reagents: i) COCJ,.; ii) 05C12; iii) R8(CH,.)qOH; iv) R6R7NH; v) R8(CH,.)qOOOOl;

vi) R8(CH2)qOCSCI; vii) R8R7NCOCI; viii) R5R7NCSCI.

Scheme E illustrates the elaboration of 50 to give carbamates and ureas, and their thio analogues. When R5 is other than a hydrogen atom, compound ~D can be converted to the corresponding carbamoyl chloride 17 or thiocarbamoyl chloride 18 by reaction with phosgene or thiophosgene. Other reagents are known in the art to be functionally equivalent to these toxic reagents and they may also be used. When R5 is hydrogen, the intermediate formed is an isocyanate or isothiocyanate, but this behaves functionally as an equivalent of the corresponding chloride. Intermediates 17 and 18 are not normally isolated, but are treated directly with alcohols to give carbamates 19 and thiocarbamates

20. Treatment of these same intermediates with amines leads to the formation of ureas
21 and thioureas 22. Alternatively, 50 may be reacted directly with a chloroformate or chlorothioformate to give the carbamate or thiocarbamate, or, when neither R6 nor R7 is hydrogen, with a chloroformamide or chlorothioformamide to give the urea or thiourea. When R6 or R7 is a hydrogen atom the chloroformamide or chlorothioformamide will tend to be unstable, in which case the isocyanate (e.g. R8-NCO) or isothiocyanate (e.g. R8-NCS) is used. As discussed previously for Scheme D, certain substituents within the embodiments of RB may require appropriate protection.

Scheme F(Scheme Removed)
Scheme F illustrates the elaboration of the side chain of the amino dicarboxylic acid series. The ~-deprotected acid 6F can be reacted under a variety of conditions with an amine to give amide 23. The condensation may be promoted by a dehydrating reagent such as a carbodiimide or a phosphorus reagent. Alternatively the acid may be converted into a more reactive derivative, such as by treatment with oxalyl chloride or thionyl chloride to give the corresponding acid chloride, which will react directly with an amine. The thicamide 24 may be obtained by treating the amide 23 with Lawesson's reagent
When all the groups have been elaborated the final protecting group is removed and the product is isolated and purified using standard techniques.

These general methods are further illustrated in the following, non limiting examples.
EXAMPLES

Abbreviations

The following abbreviations have been used.

DMF N,N-Dimethyformamide h Hour(s)
hplc High pressure liquid chromatography mm Minute(s)
pet ether Petroleum ether fraction boiling at 6O~8OoO
PYBOP (Benzotriazol-1 -yloxy)tripyrrolidinophosphonium hexafluorophosph ate PyBroP Bromotripyrrolidinophosphonium hexafluorophosphate TFA Trifluoroacetic acid
EXAMPLE I
(2S)-1 -[N~-(Pyrazinyl-2-carbonyl)-L-ornithinyI]pyrrolidine-2-carbonitrile trifluoroacetate

(Formula Removed)
A. N-(2-Nitrobenzenesulphenyl)-L-proline
L-Proline (25g, 2l7mmol) was dissolved in 2M NaCH (1 lOmL, 22Ommol) and dioxan
(i2OrnL). A solution of 2-nitrobenzenesulphenyl chloride (42g, 222mmo1) in dioxan

(GOmL) was slowly added at the same time as 2M NaOH (1 lOmL, 22Ommol). After 2h at room temperature the reaction mixture was poured into water (500mL) and the solid filtered off. The pH of the filtrate was adjusted to pH3 with 2M HOl and the solution was extracted with ethyl acetate (3 x 500mL). The combined organic extracts were washed with water (4 x 200mL) and brine (1 x 200mL), dried (Na,.504) and evaporated in vacua to give an orange solid identified as N-(2-nitrobenzenesulphenyl)-L-proline (58.lg, 2l7mmol, 100%).

B. N-(2-Nitrobenzenesulphenyl)-L-proline succinimidyl ester
N-(2-Nitrobenzenesulphenyl>-L-proline (57.9g, 2l6mmol) was dissolved in CH,.CI,.IDMF (9:1, 500mL). N-Hydroxysuccinimide (37.3g, 324mmo1) and water-soluble carbodiimide (51 .8g, 26Ommol) were added. After I 8h at room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (1 OOOmL). The solution was washed with water (4 x 200mL) and brine (1 x 200mL), dried (Na,.504) and evaporated in vacua to give a yellow solid identified as N-(2-nitrobenzenesulphenyl)-L-proline succinimidyl ester (78.9g, 2l6mmol, 100%).

C. N-(2-Nitrobenzenesulphenyl)-L-prolinamide
N-(2-Nitrobenzenesulphenyl)-L-proline succinimidyl ester (78.5g, 21 5mmol) was dissolved in dioxan (500mL). Ammonia (35%, 1 OOmL) was added. After stirring at room temperature for 2h the reaction mixture was poured into water (700mL). The precipitate was filtered off, washed with water (200niL), dried over P,.06 and recrystallised from ethyl acetate/pet ether to give a yellow solid identified as N.-(2-nitrobenzenesulphenyl)-L-prolinamide (49.Gg, l85mmoI, 88%).

D. (2S)-N-(2-Nitrobenzenesulphenyl)pyrrolidine-2-carbonitrile
N-(2-Nitrobenzenesulphenyl)-L-prolinamide (49g, lB3mmol) was dissolved in dry THF(300mL). The solution was cooled to 00C, triethylamine (36.7g. 367mmo1) was added followed by the slow addition of trifluoroacetic anhydride (77g, 367mmo1). The pH was adjusted to pH9 with triethylamine. After 30mm the reaction mixture was diluted with ethyl acetate (500mL), washed with water (1 x 200mL) and brine (1 x 200mL), dried (Na,.504) and evaporated in vacua to give an orange oil which was purified by flash chromatography (eluant: 80% pet ether, 20% ethyl acetate) to give a yellow solid identified as (2S)-N-(2-nitrobenzenesulphenyl)pyrrolidine-2-carbonitrile (38. 9g, I 5Ommol, 82%).

E. (2S)-PyrroBdine-2-carbon itrile hydrochloride
(2S)-N-(2-Nitrobenzenesulphenyl)pyrrolidine-2-carbonitrile (38.5g, 1 49mmol) was dissolved in diethyl ether (200mL). 4M HClIDioxan (1 5OrnL, 600mmol) was slowly added. After 2h at room temperature the reaction mixture was poured into diethyl ether (1 OOOmL). The solid was filtered off, washed with diethyl ether (500rnL) and recrystallised from methanol/diethyl ether to give a white solid identified as (2S)-pyrrolidine-2-carbonitrile hydrochloride (18.9g. 142.Smmol, 96%).

F. (2S)-1 -ft?-(tert-Butyloxycarbonyl)-N~-(pyraziny1-2-carbonyl)-L-omithinyl]-pyrrofidine-2-carbonitrile.
I'f~-(tert-Buloxycarbonyl)-AP-(pyrazinyl-2-carbonyl)-L-omithine (2.5g. 7.4mmol) was dissolved in CH,.C12 (5OmL). This solution was cooled to 000, (2S)-pyrrolidine-2-carbonitrile hydrochloride (1 .2g, 9.1 mmol) and PyB0P~' (4.3g, 8.23mmol) were added, and the pH adjusted to pH9 with triethylamine. After 1 8h at 000 to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (200mL). This solution was washed with 0.3M KHSO4 (2 x 5OmL), sat. NaHCO3 (2 x SOmL), water (2 x 5QmL) and brine (1 x 5OmL), dried (Na,.S04) and evaporated in vacuo to give a yellow oil. This was purified by flash chromatography (eluant 80% ethyl acetate, 20% pet. ether) to give a colourless oil identified as (2S)-1-[N~.
G. (2S)-1 -[N~-(pyrazinyI-2-carbonyl)-L-omithiny~pyrrolidine-2-carbonitrile
trifluoroacetate
(2S)-1 -[IV~-te,1-Butyloxycarbony-(pyrazinyl-2-carbonyl)-L-ornithiny~pyrrolidine-2~
carbonitrile (2.Bg, 6.7mmol) was dissolved in trifluoroacetic acid (5mL). After I h at room temperature the solvent was removed in vacuo. The residue was purified by preparative hplc (Vydac -Cl 8, 5 to 50% 0.1% TFAIa:: atonitrile into 0.1 % TFNwater over 40mm at 3mllmin). Fractions containing the product were lyophilised to give a colourless oil identified as (2S)-1-[iV0-(pyrazinyl-2-carbonyl)-L-omithinylJpyrrolidine-2-carbonitrile trifluoroacetate (1 .5g, 3.48mmol, 52%).

[M+HJ~ = 317.3
EXAMPLE 2
(2S)-1 -~Nm-(Pyrazinyl-2-carbonyI)-L-lysinyl]pyrrolidine-2-carbonitrile trifluoroacetate
(Formula Removed)
A. (N~-(tert-Butyloxycarbonyl)-N~-(9-fiuorenylmethyloxycarbonyI)-L-lysinyl)-L-

prolinamide
IV'-(tert-Butyloxycarbonyl)-N'9-(9-fluorenylmethyloxycarbonyl)-L-lysine (5g, I 0.7mmol) was dissolved in CH,.CI,. (IOOmL). The solution was cooled to 000, L-prolinamide (1 .78g, 11 .7mmol) and PyBOP (6.7g, I 2.8mmol) were added, and the pH adjusted to pH9 with triethylamine. After I 8h at 000 to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (200mL). The solution was washed with O.3M KHSO4 (2 x 5OmL), sat. NaHCO3 (2 x 5OmL), water (2 x 5OmL) and brine (I x 5OmL), dried (Na,.S04) and evaporated in vacuo. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (I-(te,t-butyloxycarbonyl)-N0-(9-fluorenyJmethyloxycarbonyl)-L-lysinyl)-L-prolinamide (4.05g, 7.2mmol, 67%).

B. (2S)-1 -(N~-(tefl-ButyloxycarbonyI)-N"'-(9-fluorenylmethyIoxycarbcrnyI)-L-lysinyl)-pyrrolidine-2-carbonitrile
(Af1-(tert-Butyloxycarbonyl)-Af0-(9-fluorenylmethyloxycarbonyl)-L-lysinyl)-L-prolinamide
(3.95g, 7.O2mmol) was dissolved in dry Ti-IF (1 OOmL). The solution was cooled to 000, triethylamine (I .4g, I4mmol) was added followed by the slow addition of trifluoroacetic anhydride (2.97g, 14.1 mmol). The pH was adjusted to pH9 with triethylamine. After 30mm the reaction mixture was diluted with ethyl acetate (I OOmL), washed with water (I x
5OmL) and brine (1 x SGmL), dried (Na,.S04) and evaporated in vacuo to give an orange oil. The residue was purified by flash chromatography (eluant: 60% pet ether, 40% ethyl acetate) to give a colourless oil identified as ~ fluorenylmethyloxycarbonyl)-L-lysinyl)pyrrolidine-2-carbonitrile (3.3g. 6.11 mmol, 87%).
C. (2S)-1 ..(Nz~(tert~ButyloxycarbonyI)~L~lysinyl) pyrrolidine-2-carbonitrile
(2S)-1 ..(I~f~(teft-Butyloxycarbonyl)-m-(9-fluorenylmethyloxycarbonyl)-L-IysinyI)pyrrolidine-
2-carbonitrile (3.1 g, 5.7mmol) was dissolved in THF (8OmL). Diethylamine (2OmL) was added. After 2h at room temperature the solvent was removed in vacua. The residue was purified by flash chromatography (eluant: 90% chloroform, 7% methanol, 3% triethylamine) to give a colourless oil identified as (2S)-1-(N~-(tert-butyloxycarbonyl)-L-lysinyl)pyrrolidine-2-carbonitrile (1 .63g, 5.O3mmol, 89%).

D. (2S)-1 -(Af~-(tert-Butyloxycarbonyl)-Nm-(pyrazinyl-2-carbonyl)-L-Iysinyl)pyrrolidine-2-carbonitrile
(2S)-1-(AJ1-(tert-Butyloxycarbonyl)-L-lysinyl)pyrrolidine-2-carbonitrile (100mg, 0.31 mmol) was dissolved in CH,.CYDMF (9:1, 2OmL). To this solution at 00C was added 1-hydroxybenzotriazole hydrate (84mg, 0.62mmol), water-soluble carbod~mide (76mg, O.38mmol), 2-pyrazinecarboxylic acid (43mg, O.3Smmol) and triethylamine (65mg, 0.O5mmoI). After 18 h at 00C to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL). This solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHOO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua to give a yellow oil. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (2S)-1 -(AP-(te,t-butyloxycarbonyl)-W0-(pyrazinyl-2-carbonyl)-L-lysinyl)pyrrolidine-2-carbonitrile (1 24mg, 0.29mmol, 93%).

E. (2S)-1 -~N"-(Pyrazinyl-2-carbonyI)-L-lysinyl]pyrrolidine-2-carbonitrile trifluoroacetate
(2S)-1 -(M'-(tert-ButyloxycarbonyI)-N~-(pyrazinyl-2-carbonyl)-L-lysinyOpyrroIidine-2-
carbonitrile (110mg, O.26mmol) was dissolved in trifluoroacetic acid (5mL). After I h at room temperature the solvent was removed in vacuo. The residue was purified by preparative hplc (Vydac 018, 5 to 50% 0.1% TFA/acetonitrile into 0.1% TFAlwater over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a colourless oil identified as (2S)-1 ..U~r.-(pyrazinyl-2-carbonyl)-L-lysinylJpyrrolidine-2-carbonitrile trifluoroacetate (66mg).
(Formula Removed)
EXAMPLE 3
(4R)-3-[N'-(Pyrazinyl-2-carbonyl)-L-lysinyljthiazolidine-4-carbonitrile trifluoroacetate
(Formula Removed)
A. (4R)-3-(tert-Butyloxycarbonyl)thiazolidine-4-carboxamide

(4R)-3-(ted-Butyloxycarbonyl)thiazolidine-4-carboxylic acid (1 2.5g,54. I mmol) was dissolved in OH,.Cl,. /DMF (9:1, 1 5OmL). To this solution at 00C was added 1-hydroxybenzotriazole hydrate (14.6g, lO8mmol) and water-soluble carbodiimide (13.Og, GSmmol). After I h at 000 ammonia (35%, 5OmL) was added. After I 8h at O~C to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (500mL). The solution was washed with 0.3M KI-1504 (2 x I OOmL), sat. NaHCO3 (2 x lOOmL), water (2 x lOOmL) and brine (1 x lOOmL), dried (Na,.504) and evaporated in vacuo to give a yellow oil. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (4R)-3-(tert-butyloxycarbonyl)thiazolidine-4-carboxamide (8.9g, 38.4mmol, 71%).

B. (4R)-Thiazolidine-4-carboxamide hydrochloride
(4S).-3-(tert-Butyloxycarbonyl)thiazolidine-4-carboxamide (8.6g, 37.1 mmol) was dissolved in 4M HCI/dioxan (5OmL). After lh at room temperature the solvent was evaporated in vacuo to give a white solid identified as (4R)-thiazolidine-4-carboxamide hydrochloride (6.2g, 36.8mmol, 99%).

C. (4R)-3-ENa~(tert~Butyloxycarbonyl)~Afo-(9..fluorenylmethyloxycarbanyl)~L.-lysinyl]-thiazolidine-4-carboxamide
N~-(tert-Butyloxycarbonyl)-Nm-(9-fluorenylmethyIoxycarbonyl)-L-lysine (5g, 1 0.7mmol) was dissolved in CH,.CI,. (lOOmL). This solution was cooled .to 00C, (4R)-thiazolidine4-carboxamide hydrochloride (1.78g, 11 .7mmol) and PyBOP (6.7g, 12.8mmol) were added, and the pH was adjusted to pH9 with triethylamine. After I 8h at 000 to room temperature the solvent was removed in vecuo and the residue was taken up in ethyl acetate (200mL). The solution was washed with 0.3M KHSO4 (2 x 5OmL), sat. NaHCO3 (2 x 5OmL), water (2
x 5OmL) and brine (1 x 5OmL), dried (Na,.504) and evaporated in vacua to give a yellow oil.
The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified as (4R)-3-~Af-(tert-butyloxycarbonyl)-Nm-(9-fluorenyl-methyloxycarbonyl)-L-lysiny~thiazolidine-4-carboxamide (2..8 1g. 4.8mmol, 44%).

D. ~
thiazolidine-4-carbonitrile
(4R)-3-[N~'-(tert-Butyloxycarbonyl)-m-(9-fluorenylmethyloxycarbonyl)-L-lysinyl]thiazolidine-4-carboxamide (2.7g, 4.7mmol) was dissolved in dry THF (lOOmL). The solution was cooled to 000, triethylamine (1.0g. 1 Ommol) was added followed by the slow addition of trifluoroacetic anhydride (2.Og, 9.Smmol). The pH was adjusted to pH9 with triethylamine. After 30mm the reaction mixture was diluted with ethyl acetate (lOOmL), washed with water (1 x 5OmL) and brine (1 x 5OmL), dried (Na,.S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 60% pet ether, 40% ethyl acetate) to give a colourless oil identified as (4R)-3-~Af~-(tert-butyloxycarbonyl)-IV0-(9-fluorenylmethyl-oxycarbonyl)-L-lysinylJthiazolidine-4-carbonitrile (2.14g, 3.81 mmol, 82%).

E. (4R)-3-(N'~-(tert-Butyloxycarbonyl)-L-lysinylJthiazolidine-4-carbonitrile
(4R).-3.{AfL.-(tert.-ButyIoxycarbonyI)~A/ID.-(9~fluorenylmethyloxycarbonyl).-L..lysinyl]thiazolidmne..
4—carbonitrile (1 .9g, 3.4mmol) was dissolved in Ti-IF (4OmL). Diethylamine (1 OmL) was added. After 2h at room temperature the solvent was removed in vacua. The residue was purified by flash chromatography (eluant: 90% chloroform, 7% methanol, 3% triethylamine) to give a colourless oil identified as (4R).-3-fAfL~(ted-butyloxycarbonyl)~L-lysinyl)thiazolidine-4-carbonitrile (863mg, 2.Smmol, 75%).

F.. ~
4-carbonitrile
(4R)~3.-(ML.-(tert.-Butyloxycarbonyl)~L.-lysinyl]thiazolidine..4..carbonitrile (100mg, 0.29mmol) was dissolved in CH,.CI,. (2OmL). To this solution at 000 2-pyrazinecarboxylic acid (43mg, 0.3Smmol) and PyBOP (170mg, 0.33mmol) were added and the pH was adjusted to pH9 with triethylamine. After 18 h at O~C to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). The solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 2% methanol, 98% chloroform) to give a colourless oil identified

as (4R)-3-(N~-(tert-butyloxycarbonyl)-Af-(pyrazinyl-2-carbonyl)-L-lysinyl]thiazolidine-4-carbonitrile (112mg, O.2Smmol, 86%).

G. (4R)-3-[N -(Pyrazinyl-2-carbonyl)-L-lysinylJthiazolidine-4-carbonitrile
trifluoroacetate
(4R)-3-[M1-(tert-Butyloxycarbonyl)-/V~-(pyrazinyl-2-carbonyl)-L-lysinyl]thiazolidine-4-
carbonitrile (110mg, 0.26mmol) was dissolved in trifluoroacetic acid (5mL). After 1 h at room temperature the solvent was removed in vacua. The residue was purified by preparative hplc (Vydac 018, 5 to 50% 0.1% TFAlacetonitrile into 0.1% TFAlwater over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a colourless oil identified as (4R)-3-{Nm-(pyrazinyl-2-carbonyl)-L-lysinyl]thiazolidine-4-carbonitrile trifluoroacetate (57mg).

[M+H]4 = 349.1

EXAMPLE 4
(2S)-1 -[W~-(Pyridyl-3-methyI)-L-glutaminy~pyrro1idine-2-carbonitriIe clihydrochlonde
(Formula Removed)
A. (2S)-1 -[N-(tert-Butyloxycarbonyl)-O'~-methyl-L-glutamylJpyrrolidine-2-carbonitrile N-(tert-Butyloxycarbonyl)-00'-methyl-L-glutamic acid (1 .Og, 3.B3mmol) was dissolved in
• CH2CI,. /DMF (9:1, 2OmL). To this solution at 000 were added 1-hydroxybenzotriazole hydrate (788mg, 5.84mmol), water-soluble carbodiimide (877mg, 4.38mmol), (2S)-pyrrolidine-2-carbonitrile hydrochloride (609mg, 4.6mmol) and tuiethylamine (65mg, 0.6Smmol). After I 8h at 000 to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL), this solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua. The residue was purified by flash chromatography• (eluant: 50% ethyl acetate, 50% pet. ether) to give a brown oil identified as (2S)-1-[N-(tert-

butyloxycarbonyl)-002-methyl-L-glutamyl]pyrro[idine-2-carbonitrile (290mg, 0.B6mmol, 22%).

B. (2S)-i -[N-(terl-Butyloxycarbonyl)-L-g lutamyljpyrrolidine-2-carbonitrile
(23)-I -{N-(te,t-Buty1oxycarbonyJ)-0'~-methyl-L-g lutamylJpyrrolidine-2-carbonitrile (250mg, O.74mmol) was dissolved in dioxan (5mL). IM Lithium hydroxide (1.lmL, 1.lmmol) was added. After 1 h at room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). This solution was washed with I M KHSO4 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua to give a colourless oil identified as (2S)-1-(N-(tei't-butyloxycarbonyl)-L-glutamyl]pyrrolidine-2-carbonitrile (200mg, O.6lmrnol, 83%).

C. (2S)-1 .{N'~-(tert..Butyloxycarbonyl)..W0-(pyridyl..3-methyl)..L-glutaminyl]pyrrolidine. 2-carbonitrile
(23)-I -[N-(te,t-Butyloxycarbonyl)-L-glutamyljpyrrolidine-2-carbonitrile (30mg, O.O93mmol) was dissolved in CH,.CI,./DMF (9:1, lOmL). To this solution at 00C was added 1-hydroxy-benzotriazole hydrate (21mg, O.ISmmol), water-soluble carbodiimide (21mg, 0.lOSmmol), 3-(aminomethyl)pyridine (11mg, 0.lmmol) and tiiethylamine(2Omg, 0.2mmol). After I 8h at 000 to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). The solution was washed with O.3M KHSO4 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua to give a yellow oil. The residue was purified by flash chromatography (eluant: 5% methano, 97% chloroform) to give a colourless oil identified as (2S~-1 -[PJ~-(tert-butyioxycarbonyl)-M~-(pyridyl-3-methyl)-L-gIutaminylJpyrrolidine-2-carbonitrile (16.6mg, O.O4mmol, 44%).

D. (2S)-1 -[N"'-(Pyridyl-3-methyl)-L-glutaminylJpyrrolidine-2-carbonitrile dihydrochloride
(2S)—1 -(N~-(te,t..Butyloxycarbonyl)-N~-(pyridyl-3-methyl)-L-gIutaminyl]pyn-olidine-2..
carbonitrile (17mg, 0.O4mmol) was dissolved in 4M HOI/dioxan (5mL). After lh at room temperature the solvent was removed in vacua to give a white solid identified as (23)-I-fAP-(pyridyl-3-methyl)-L-glutaminyl]pyrrolidine-2-carbonitrile dihydrochloride (17mg, 0.O4mmol, 100%).

[M+HJ~ 316.2
EXAMPLE 5
I -[tiP-(Pyrazinyl-2-carbonyl)-L-omithinyl]pyrrolidine trifluoroacetate

(Formula Removed)
A. I -[N"-(Benzyloxycarbonyl)-N~-(tefl-butyl6xycarbonyI)-L-ornithinylJpyrrolidine iV'~-(Benzyloxycarbonyl)-Af~-(tei~-butyloxycarbonyl)-L-ornithine (5.49g, 1 Smmol) was dissolved in CH,.CI,. /DMF (9:1, 1 OOmL). To this solution at 0~O was added 1-hydroxybenzotriazole hydrate (3.37g, 22mmol), water-soluble carbodiimide (3.46g, l8mmol), pyrrolidine (1.28g. l8mmol) and triethylamine (200mg, 2Ommol). After 18h at 000 to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (200mL). The solution was washed with 0.3M KHSO4 (2 x SGmL), sat. NaHCO3 (2 x 5OmL), water (2 x 5OmL) and brine (1 x 5OmL), dried (Na,.S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 90% ethyl acetate, 10% pet. ether) to give a colourless oil identified as 1-fAf~-(benzyloxycarbonyl)~NcL~(tert~butyloxycarbonyl).-L~ornithinylJpyrrolidine (5.1 5g, I 2.3mmol, 82%).

6.1 -[W-(tert-Butyloxycarbonyl)-L-omithinyl]pyrrolidine
I -ENm-(Benzyloxycarbonyl)-N~-(tert-butyloxycarbonyl)-L-omithinylJpyrrolidine (2.1 5g,
5.1 3mmol) was dissolved in methanol (BOmL). This solution was hydrogenated over 10%
Pd/C (400mg). After 2h the catalyst was filtered off and washed with methanol (SGmL).
The combined.fiitrates were evaporated in vacua to give an off white solid identified as 1-

EN'1-(te,t-butyloxycarbonyl)-L-ornithinyUpyrrolidine (I .35g, 4.74mmol, 94%).

C. I -[N~-(tert-Butyloxycarbonyl)-IV-(pyraziny1-2-carbonyl)-L-ornithinyl]pyrrolidine
I -pV1-(tert-Butyloxycarbonyl)-L-omithinyupyrrolidine (100mg, 0.3Smmol) was dissolved in
CH,.CI,. (2omL). To this solution at 00C were added PyBroP (195mg, 0.4mmol), 2-
pyrazinecarboxylic acid (50mg, 0.4mmol) and tijethylamine (100mg, 1 .Ommol). After I 8h at 00C to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). The solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHOO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 3% methanol, 97% chloroform) to give a sticky white solid identified as 1.-[Na~(tert~ butyloxycarbonyl)-Af0-(pyrazinyl-2.-carbonyl).-L.-omithiny;Jpyrrolidine (90mg, 0.2Smmol, 66%).

D. I -[N"-(Pyrazinyl-2-carbonyl)-L-ornithiny~pyrrondjne trifluoroacetate
I ~ (90mg, 0.23mmol) was dissolved in.4M HOI/dioxan (l5mL). After 45mm at room temperature the solvent was removed in vacuo. The residue was purified by preparative hplc (Vydac 018, 5 to 50% 0.1% TFA/acetonitrile into 0.1% TFA/water over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a colourless oil identified as 1-(AP~-(pyrazinyl-2-carbonyl)-L-ommthmnyljpyrrolidine trifluoroacetate (51mg).
(Formula Removed)

EXAMPLE 6
3-[Nm-(Pyrazrnyl-2-carbony1).-L~on1itiiiny~thiazolidine trifluoroacetate

(Formula Removed)
ornithinyl]thiazolidine

was dissolved in CI-l,.CI,. IDMF (9:1, 1 OOmL). To this solution at 000 were added 1-hydroxybenzotriazole hydrate (1 .53g, 1 Ommol), water-soluble carbodiimide (1 .34g,

7mmol), thiazolidine (1 .28g, I 8mmol) and triethylamine (80mg, 8mmol). After I 8h at 0~C to~ room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (lOOmL). The solution was washed with 0.3M KHSO4 (2 x 25mL), sat. NaHCO3 (2 x 25mL), water (2 x 25mL) and brine (1 x 25mL), dried (Na,.504) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 75% ethyl acetate, 25% pet. ether) to give a white solid identified as 3~(Na.-(tert-buty1oxycarbonyl)-N'~-(9-fluorenylmethyloxycarbonyl)-L-omithinyl]thiazolidine (2.55g. 4.8Smmol, 81%).

B. 3-[N~-(tert-8utyloxycarbonyl)-L-omithinyl]thiazolidine
N~-(tert-Butyloxycarbonyl)-Nm-(9-fluorenylmethyloxycarbonyl)-L-ornithiny1Jthiazolidine
(1.15g, 2.l3mmol) was dissolved in acetonitrile (2OmL). Diethylamine (5mL) was added. After 90mm at room temperature the solvent was removed in vacua and the residue was purified by flash chromatography (eluant: 90% chloroform, 7% methanol, 3% triethylamine) to give a pale yellow oil identified as 3-[N'~-(tert-butyloxycarbonyl)-L-omithinyl]thiazolidine (530mg, 1 .67mmol, 78%).

C. 3-ElV't-(te,1-Butyloxycarbonyl)-Ar-(pyrazinyl-2-carbonyl)-L-omithmnyljthiazolidine
3-[N'~-(te,t-Butyloxycarbonyl)-L-omithinylJthiazoIidine (80mg, O.27mmol) was dissolved in CH,.CI,. (2OmL). To this solution at 00C were added PyBroP'~ (146mg, 0.3mmol), 2-pyrazinecarboxylic acid (37mg, 0.3mmol) and triethylamine (90mg, O.9mmol). After 18h at 00C to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL). The solution was washed with O.3M KH504 (2 x 2OmL), sat NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na,.504) and evaporated in vacuo. The residue was purified by flash chromatography (eluant 3% methanol, 97% chloroform) to give a sticky white solid identified as 3-(AI~-(tert-butyloxycarbonyl>-N-(pyrazinyl-2-carbonyl)-L-omithinyl]thiazolidine (45mg, 0.11 mmol, 41%).

D. 3-[N-{PyrazinyI-2-carbony4-L-ornithiny~thiazolidine trifluoroacetate
3-(Af2-(tert-Butyloxycarbonyl)-/'f"-(pyrazinyl-2-carbonyl)-L-omithinyljthiazolidine (4 5mg,
0.1 Immol) was dissolved in 4M HOI/dioxan (lOmL). After 45mm at room temperature the
solvent was removed in v~cuo. The residue was purified by preparative hplc (Vydac C18,
5 to 50% 0.1% TFA/acetonitrile into 0.1% TFAlwater over 40mm at 3mLlmin). Fractions
containing the product were lyophilised to give a colourless oil identified as 3-[Nm-(pyrazinyl-2-carbonyl)-L-om ithinyl]thiazolidine trifluoroacetate (14mg).

[M+H]~ = 310.0

EXAMPLE 7
(2S)-i ~[S-(Acetylaminomethy~~L-cysteinyl]pyrrolidine-2-carbonitrile trifluoroacetate
(Formula Removed)
A. (2S)-1 -[S-(Acetylaminomethyl)-N-(tert-butyloxycarbonyl)-L-cysteinylJpyrrolidine-2-carbonitrile
S-(Acetylaminomethyl)-N-(tert-butyloxycarbonyl)-L-cysteine (660mg, 2.26mmol) was dissolved in OH,.Ol,. (3OmL). To this solution at 000 were added (2S)-pyrrolidine-2-carbonitrile hydrochloride (250mg, 1 .B9mmol) and PYBOP (1 .3g, 2.49mmol), and the pH adjusted to pH9 with triethylamine. After 18h at 000 to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (1 5OmL). The solution was washed with 0.3M KHSO4 (2 x 3OmL), sat. NaHCO3 (2 x 3OmL), water (2 x 3OmL) and brine (1 x 3OmL), dried (Na,.S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 75% ethyl acetate, 25% pet. ether) to give a colourless oil
identified as (23)-I -[S-(acetylaminomethyl)-N-(tert-butyloxycarbonyO-L-cysteinylj
pyrrolidine-2-carbonitrile (650mg, 1 .7Gmmol, 78%).
B. (2S)-1 -[S-(Acetylaminomethyl)-L-cysteinyljpyrrolidine-2-carbonitrile trifluoroacetate
(2S)-1 -[S-(Acetylaminomethyl)-N~(tert-butyloxycarbonyl)-L-cysteinyl]pyrrolid ine-2-
carbonitrile (610mg, 1 .65mmol) was dissolved in trifluoroacetic acid (3OmL). After I h at room temperature the solvent was removed in vacua to give a colourless oil identified as (2S>I -[S-(acetylaminomethyl)-L-cysteinyl]pyrrolidine-2-carbonitrile trifluoroacetate (620mg, 1.61 mmol, 98%).
EXAMPLE 8
(2S)-1 -[(2'R)-3'-(Acetylaminomethylthio)-2'-amino-3'-methylbutanoyl]pyrrolidine-2-
carbonitrile trifluoroacetate
(Formula Removed)
A. (2S)-1 -[(2'R)-3'-(Acetylaminomethylthio)-2'-(tefl-butyloxycarbonylamino)-3'-methylbutanoyl]pyrrolidine-2-carbonitrile S-(Acetylaminomethyl)-N-(tert-butyloxycarbonyl)penicilla mine (720mg, 2.2Smmol) was dissolved in CH,.CI,. (3OmL). To this solution at 000 were added (2S)-pyrrolidine-2-carbonitrile hydrochloride (270mg, 2..O4mmol) and PyBOP (1 .3g, 2.4Smmol), and the pH adjusted to pH9 with triethylamine. After 18h at 00C to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (1 5OmL). The solution was washed with O.3M 1(1-ISO4 (2 x 3OmL), sat. NaHCO3 (2 x 3OmL), water (2 x 3OmL) and brine (1 x 3OmL), dried (Na2S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 75% ethyl acetate, 25% pet. ether) to give a colourless oil identified as (23)-I -[(2'R)-3'-(acetylaminomethylthio)-2'-(teit-butyloxycarbonylamino)-3'-methylbutanoyl]pyrrolidine-2-carbonitrile (742mg, 1 .86mmol, 83%).

B. (2S)-1 ~[(2'R)..3-(Acetylaminomethylthio)-2'-amino-3'-methylbutanoylIpyrroiidine-2-carbon Etrile trifluoroacetate
(2S)-1 ~
butanoy~pyrrolidine-2-carbonitrile (710mg, 1.78mmoI) was dissolved in trifluoroacetic acid (3OmL). After I h at room temperature the solvent was removed in vacua to give a colourless oil identified as (2S)-i ~[(ZR)~3-(acetylaminomethylthio)-2'-amino-3'-rnethyl-butanoylJpyrrolidine-2-carbonitrile trifluoroacetate (560mg, 1 .36mmol, 76%).

(Formula Removed)
EXAMPLE 9
(2S)-1 -[N~-(2-Chloropyridyl-3-carbonyl)-L-omithinyI] pyrrolidine-2-carbonitrile trifluoroacetate(Formula Removed)
A. (2S)-1 -(IiP-(tert-Butyloxycarbonyl)-L-ornithyl)pyrrolidine-2-carbOnitrile
(2S)-1 -(N~-(tert-Butyloxycarbonyl)-L-ornithyl)pyrrolidine-2-carbonitrile was prepared by the method described for the lysine derivative in Example 2.

B. (2S)-1 -(N~-(tert-Butyloxycarbonyl)-IV"-(2-chloropyridyI-3-carbOflyl)-L-OTflithyI)-pyrrolidine-2-carbonitrile
(2S)-1 -(N~-(te,t-Butyloxycarbonyl)-L-omithyl)pyrrolidine-2-carbOnitrile (80mg, 0.2Gmmol) was dissolved in CH2012 (2OmL). To this solution was added 2-chloropyridine-3-carbonyl chloride (55mg, 0.32mmol) and the pH adjusted to pH9 with triethylamine. After I 8h at room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). The solution was washed with 0.3M KHSO4 (2 x 2OmL), sat. NaHOO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na2S04) and evaporated in vacua. The residue was purified by flash chromatography (eluant 95% ethyl acetate, 5% pet. ether) to give a colourless oil identified as (2S)-1 -(Af~-(tert-butyloxycarbonyl)-N-(2-chloropyridyl-3-carbonyl)-L-ornithyi)pyrrolidine-2-carbonitrile (60mg, 0.1 4mmol, 53%).

C. (2S)-1 -[AF"-(2-Chloropyridyl-3-carbonyl)-L-omithinyl]pyrrolidifle-2-CarbOflitrile trifluoroacetate
(2S)-1 ~
carbonitrile (60mg, 0.l4mmol) was dissolved in trifluoroacetic acid (5mL). After lh at room temperature the solvent was removed in vacua. The residue was purified by
(Formula Removed)
preparative hplc (Vydac C18, 5 to 50% 0.1% TFA/acetonitrile into 0.1% TFAlwater over 40mm at 3mLlmin). Fractions containing the product were lyophilised to give a white solid identified as (23)-I ~ trifluoroacetate (52mg).

[M+HJ4 350.1
EXAMPLE 10
I -[N~-(2-Chloropyndyl-3-carbonyl)-L-ornithinyl]pyrrolidine hydrochloride
A. I -(M-(lert-Butyloxycarbonyl)-N"'-(2-chloropyridyl-3-carbonyl)-L-ornithyl)-pyrrolidine
I -( tert-Butyloxycarbonyl)-L-omithyl)pyrrolidine (20mg, 0.O69mmol) was dissolved in 01-12012 (5mL). To this solution was added 2-chloropyridine-3-carbonyl chloride (14mg, 0.O76mmol) and the pH adjusted to pH9 with triethylamine. After lh at room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL). The solution was washed with O.3M KI-1S04 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na2SO4) and evaporated in vacua. The residue was purified by flash chromatography (eluant: 10% methanol, 90% dichioromethane) to give a colourless oil identified as I -(Ai'~-(tert-butyloxycarbonyl)-Af0-(2-chloropyridyJ-3-carbonyl)-L-omithyl)pyrrolidine (19mg, 0.O4Smmol, 63%).

B. I ~ hydrochloride
1 -PV'~-(te,t-Butyloxycarbonyl)-M'-(2-chloropyridyl-3-carbonyl)-L-omithinyl]pyrrolidine (19mg,
0.O4SmmoI) was dissolved in 4M HOI/dioxan (lOmL). After 45mm at room' temperature
the solvent was removed in vacua to give a white solid identified as 1-(N~-(2-chloropyridyl-
3-carbonyl)-L-omithinyljpyrrolidine hydrochloride (15mg):

(Formula Removed)
[M+H]~ = 325.1
EXAMPLE 11
~ hydrochloride

A. ~ ithyl)thiazolidine
~ (136mg, 0.45mmol) was dissolved in 0H2C12 (1 OmL). To this solution was added 2-chloropyridine-3-carbOnyl chloride (88mg, Q.5mmol) and the pH adjusted to pH9 with triethylamine. After lh at room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (7OmL). The solution was washed with O.3M KHSO4 (2 x 2OmL), sat. NaHCO3 (2 x 2OmL), water (2 x 2OmL) and brine (1 x 2OmL), dried (Na2SO4) and evaporated in vacuo. The residue was purified by flash chromatography (eluant: 1.5% methanol, 98.5% dichloromethane) to give a colourless oil identified as ~ L-ornithyl)thiazolidine (30mg, 0.O68mmoI, 15%).

B. ~ iazolid me hydrochloride
~ jazolidine
(30mg, 0.O68mmol) was dissolved in 4M HOI/dioxan (lOmL). After 45mm at room temperature the solvent was removed in vacuo to give a white solid identified as 1-(N~-(2-chloropyridyl..3~carbonyl)~L~Orflithinyl]thiaZOlidine hydrochloride (25mg).

[M+H]~ = 342.1
EXAMPLE 12
(2S)-1 -[S-(3-Picolylcarbamoylmethyl)-L-cysteinyl]pyrrolidmne-2-carbonitrile
trifluoroacetate(Formula Removed)
A. S-(Benzyloxycarbonylmethyl)-N-(tert-butyloxycarbonyl)-L-cysteine N-(tert-Butyloxycarbonyl)-L-cysteine (3.5g, I 5.Bmmol), benzyl 2-bromoacetate (3Jg, 16.1 mmcl) and triethylamine (1 .Bg, I 8.Ommol) were dissolved in THF (1 OOmL). After 18 hours at room temperature the reaction mixture was diluted with ethyl acetate (lOOmL), washed with O.3M KHSO4, sat NaHCO3, water and brine, dried (Na2SO4) and evaporated. The residue was purified by flash chromatography (eluant 95% chloroform, 4% methanol, 1% acetic acid) yielding a colourless oil identified as S-(benzyloxycarbonylmethyl)—N-(te,tbutyloxycarbonyl)-L-cysteine (5.2g, 14.1 mmol, 89%).

B. (2S)-1 -[S-(Benzyloxycarbonylmethyl)—N-(tefl-butyloxycarbonyl)-L-cystemnyl]pyrrolidine-2-carbonitrlle S-(Benzyloxycarbonylmethyl)---N-(tert-butyloxycarbonyl)-L-cystemne (5.1 Og, I 3.8mmol) was dissolved in CH2012 (200mL). This solution was cooled to 000, (2S)-pyrrolidine-2-carbonitrile hydrochloride (2.lg, 15.Bmmol) and PyBOP (8.Og, 15.Smmol) were added, and the pH was adjusted to pH9 with triethylamine. After I 8h at 0~C to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (l5OmL). This solution was washed with O.3M 1(1-ISO4 (1 x 5OmL), sat. NaHOO3 (1 x 5OmL), water (1 x 5OmL) and brine (1 x 5OmL), dried (Na2S04) and evaporated in vacua to give a yellow oil. This was purified by flash.chromatography (eluant: 40% ethyl acetate, 60% pet. ether) to give a colourless oil identified as (2S)-1-[S-(benzyloxycarbonylmethyl)—N-(tert-butyloxycarbonyl)-L-cysteinyl]pyrrolidmne-2-carbonitrile (5.82g, I 3.Ommol, 94%).
C. (2S)-I ~
carbonitrile
(2S)-1 ~~S~(Benzyloxycarbonylmethyl)—N-(tert-butyloxycarbOnyl)-L-cysteinyl]pyrrOlidmne-2-

carbonitrile (1.31g. 2.9mmol) was dissolved in THF(1 OOmL). Aqueous lithium hydroxide (1 M, 3.5mL, 3.Smmol) was added. After 3 hours at room temperature the reaction mixture was diluted with ethyl acetate (1 OOmL), washed with I M citric acid, water and brine, dried (Na2SO4) and evaporated in vacua to give a colourless oil. This was purified by flash chromatography (eluant: 97% chloroform, 2% methanol, 1% acetic acid) to give a colourless oil identified as (2S)-1 -(N-(tert-butyloxycarbonyl)-S-(carboxymethyD—Lcystemnyl]pyrrolidmne-2-carbonitrile (860mg, 2.4mmol, 82%).

0. (2S)-I - [N~(tert~Butyloxycarbonyl)~S~(3-picolylCarbamoylmethyl)-L-cy5teinylJ-pyrrolidmne-2-carbonitrile
(2S)-1 ~[N~(tert~Butyloxycarbonyl)-S-(carboxymethyI)—L-cysteinyl]pyJTOlidine-2-carbonitrile (150mg, O.42mmol) was dissolved in 0H2C12 (2OmL). This solution was cooled to 000, 3~ (ammnomethyl)pyridine (53mg, O.Smmol) and PyBOP (270mg, O.52mmol) were added, and the pH adjusted to pH9 with triethylamine. After 18h at 000 to room temperature the solvent was removed in vacua and the residue was taken up in ethyl acetate (7OmL). This solution was washed with O.3M KHSO4 (1 x 2OmL), sat Nal-1003 (1 x 2OmL), water (1 x 2OmL) and brine (1 x 2OmL), dried (Na2S04) and evaporated in vacua to give a yellow oil. This was purified by flash chromatography (eluant 96% chloroform, 4% methanol) to give a colourless oil identified as (2S)-1-EN-(ted-butyloxycarbonyl)-S-(3-picolylcarbamoylrnethyl)~L-cysteinyUpyrrolidine-2-carbOnitrile (170mg, 0.3Bmmol, 91%).

E. (2S)-1 ~[S~(3-PicoIylcarbamoylmethyl)-L-cystemnyl]pyrrOlidifle-2-carbOnitFile trifluoroacetate
(2S)-1 ~ carbonitrile (130mg, 0.29mmol) was dissolved in trifluoroacetic acid (1 OmL). After 1 hour at room temperature the solvent was removed in vacua to give a white solid identified as (2S)-1 ~ trifluoroacetate (11 6mg,0.2Smmol, 86%).

(M+Hjt = 348.2

EXAMPLE 13
3-fN~-(2-QuinoxaloyI)-L-lysinyl]thiazolidine hydrochloride

(Formula Removed)
3-[M1-(tert-Butyloxycarbony~lysinyl]thiazolidine (128mg, 0.4mmol) was dissolved in CH2CI2 (1 OmL). 2-Quinoxaloyl chloride (85mg, O.44mmol) and potassium carbonate (45.8mg, O.3mmol) were added. The reaction mixture was stirred at room temperature for 18 hours and the solvent removed in vacuo. The residue was purified by flash chromatography (eluant 99.5% chloroform, 0.5% methanol) to give a colourless oil identified as 3-[tf-(fert-butyloxycarbonyl)-Af0-(2-quinoxaloyl)-L-lysinyl]thiazolidine (140mg, 0.29Gmmol, 74%).

B. 3-[Ar~-(2-Quinoxaloyl)-L-lysinyl]thiazolidine hydrochloride 3-[AP-(telt-Butyloxycarbonyl)-Nm-(2-quinoxaloyl)-L-lysinylJthiazolidine (140mg, 0.296mmo1) was dissolved in 4M HOI/dioxan (2OmL).. After 1 hour at room temperature the solvent was removed in vacuo to give a white solid identified as ~ lysinylJthiazolicline hydrochloride (128mg, 0.296mmo1, 100%).

[M+H]~ = 374.2
(Formula Removed)
EXAMPLE 14
3-[W"-(3-Pyridyloxycarbonyl)-L-omithinyl]thiazolidine hydrochloride
A. 3-[W-(tert-Butyloxycarbonyl)-N8-(3-pyridyloxycarbonyl)-L-omithinyl]thiazolidine
3-Hydroxypyridine (14.9mg, 0.l38mmol) was dissolved in 0H2C6 (2OmL). Phosgene (20% solution in toluene, 0~335mL, O.6BSmmol) and pyridine (14mg, 0.lB2mmol) were added at 000. After 90 mins the solvent was removed in vacuo and the residue dissolved in CH2CI2 (2OmL). 3-[Nm-(tert-Butyloxycarbonyl)ornithinyl]thiazolidine (42mg, 0.1 38mmol) and triethylamine (28mg, 0.28mmol) were added. The reaction mixture was stirred at room temperature for 18 hours and the solvent removed in vacuo. The residue was purified by flash chromatography (eluant: 970/o chloroform, 3% methanol) to .give a colourless oil identified as 3-(AC-(tet-butyloxycarbonyl)-N-(3-pyridyloxycarbonyl)-L-ornithinyl]thiazolidine (16mg, 0.O38mmol, 27%).

B.. 3-[It-(3-Pyridyloxycarbonyl)-L-omithinyljthiazolidine hydrochloride
3-fM~-(te,t-Butyloxycarbonyl)-N~-(3-pyriclyloxycarbonyl)-L-omithiny~thiazolidine (16mg, 0.O38mmol) was dissolved in 4M HOl/dioxan (2OmL). After 1 hour at room temperature the solvent was removed in vacuo to give a white solid identified as 3-[M"-(3-pyridyloxycarbonyl)-L-omithinyl]thiazolidine hydrochloride (14mg, 0.O38mmol, 100%).
(Formula Removed)
EXAMPLE 15
3-[O-(3-Chlorobenzylcarbamoyl)seriny~thiazolidine hydrochloride

A. 3-[N-(tert-Butyloxycarbonyl)—L-serinyljthiazolidine
N-(teit-Butyloxycarbonyl)-L-serine (2.1 g, I 0.2mmol) was dissolved in CH2CI2IDMF (9:1 ,5OmL). Thiazolidine (650mg, 11 .2mmol), hydroxybenzotriazole(2.8g, 20.7mmol) and water soluble carbodiimide (3.9g, 19.Smmol) were added at 00C. The pH was adjusted to pH8 with N-methylmorpholine. The reaction mixture was stirred at room temperature for 18 hours, the solvent removed in vacuo and the residue was taken up in ethyl acetate (1 5OmL). This solution was washed with 0.3M 1(1-ISO4 (1 x 5OrnL), sat NaHCO3 (1 x 5OmL), water (1 x 5OmL) and brine (1 x 5OmL), dried (Na2SO4) and evaporated in vacuo to give a white solid identified as 3-(N-(teft-butyloxycarbonyl)-L-serinyUthiazolidine (2.15g, 7.7Bmmol, 76%).

B. 3-[N-(iert-Butyloxycarbonyl)—O-(3-chlorobenzylcarbamoyl)-L-serinyl]thiazolidine 3-[N-(tert-Butyloxycarbonyl)-L-serinyl]thiazolidine (110mg, 0.4Bmmol) was dissolved in DMF (lOmL) and 1,1'-carbonyl-diimidazole (71mg, 0.43mmol) was added. After 2 hours at room temperature 3-chlorobenzylamine (62mg, 0.4mmol) was added. After a further 18 hours EtOAc (200mL) was added. This solution was washed with 0.3M 1(1-ISO4 (1 x 5OmL), sat. NaHOO3 (1 x 5OmL), water (4 x 5OmL) and brine (1 x 5OmL), dried (Na2S04) and evaporated in vacuo to give a yellow oil. This was purified by flash chromatography (eluant 40% ethyl acetate, 60% pet. ether) to give a colourless oil identified as 3-(N-(tert-butyloxycarbonyl)-O-(3-chlorobenzylcarbamoyl)-L-serinyl]thiazolidine (158mg, 0.36mmol, 90%).
C. 3-[O-(3-Chlorobenzylcarbamoyl)-L-sennyl]thiazolidine hydrochloride 3-[N-(te,t-Butyloxycarbonyl)-O-(S-chlorobenzylcarbamoyl)-L-sennyljthiazolidine (140mg, 0.32mmol) was dissolved in 4M HOI/dioxan (2OmL). After 1 hour at room temperature the solvent was removed in vacuo to give a white solid identified as 3-[O-(3-chlorobenzylcarbamoyl)-L-serinyl]thiazolidine hydrochionde (115mg, 0.3mmol, 94%).

tM+H1~ = 344.1

The Examples set out in the following Tables were prepared by analogous methods to the above.
TABLE I — Examples 16— 162
(Table Removed)

TABLE 2— Examples 163 —250
(Table Removed)

TABLE 3— Examples 251 — 266

(Table Removed)
TABLE 4— Examples 267 — 318

(Table Removed)
TABLE 5— Examples 319 — 378
(Table Removed)
TABLE 6— Examples 379 —418
(Table Removed)
TABLE 7— Examples 419 — 438
(Table Removed)

TABLE 8— Examples 439 — 450
(Table Removed)

EXAMPLE 451
Determination of activity

Oompounds were assayed as inhibitors of DP-IV according to the methods described in W095/1 5309. All the compounds described in the foregoing Examples were competitive inhibitors of DP-IV with 1'~ values less than 300nM.
EXAMPLE 452
Determination of activity in vivo
The anti-diabetic action of selected compounds was demonstrated in Zucker obese rats using a standard oral glucose tolerance test. Oontrol rats were given a solution of glucose by oral gavage, and plasma glucose levels were determined. These rats demonstrated a significant hyperglycaemia. Oompounds according to the present invention were dissolved in glucose solution at various concentrations, such that the rats could be given
varying doses of the compound simultaneously with the glucose challenge. The hyperglycaeinic excursion was reduced in a dose-dependent manner in animals receiving between 0.1 and 100 mg/kg of DP-IV inhibitor.
EXAMPLE 453
Pharmaceutical formulation

Tablets containing 100mg of the compound of Example I as the active agent are prepared from the following:
Oompound of Example I 200.Og
Oorn starch 71.Og
Hydroxypropylcellulose 18.Og
Oarboxymethylcellulose calcium 13.Og
Magnesium stearate 3.Og
Lactose 195.Og
Total 500. Og

The materials are blended and then pressed to give 2000 tablets of 250mg, each containing 100mg of the compound of Example 1.
The above demonstrates that the compounds according to the present invention are inhibitors of DP-IV and would accordingly be expected to be useful as therapeutic agents for the treatment of impaired glucose tolerance, type II diabetes, and other diseases where inhibition of this enzyme leads to an improvement in the underlying pathology or the symptoms.

We claim:

A compound selected from derivatives of formula I that are inhibitors of the enzyme of dipeptidyl peptidase IV, its tautomers and stereoisomers thereof, and pharmaceutically acceptable salts of said derivatives, tautomers and isomers
(Formula Removed)

wherein:

X' is selected from a sulphur atom, an oxygen atom, a sulphinyl group, a sulphonyl group and a methylene group;
X2 is methylene;
X3 is either a carbonyl or thiocarbonyl group;

R1 is either a hydrogen atom or a nitrile group;

R2 and R3 are independently selected from K and C1-C6 alkyl, or together may be -(CH2)p.;

R4 is R6 R7 N;

R' and R7 are selected independently from R8(CH2)q or together they are(CHz)2-Z'- (C1-C2)- or -CHR9 -Z2CHz-CI-tR'0-;

R8 is selected from H, C1-C6 alkyl, benzo- fused cyclo (C1-C6)alkyl, (C1-C6) alkyl-to acyl, di (C1-C6) alkylamino, N- (C1-C6)alkylpiperidyl, substituted aryl, optionally substituted alkylbenzyl, optionally substituted aroyl, and optionally substituted arylsulphonyl

R9 and R'0 are selected independently from H, carbamoyl, hydroxymethyl and cyanomethyl;

Z' Is selected from a covalent bond, -(CHz)r-, -o-, -sot- and - N((CHz)qR8)
(Formula Removed)
Z2 is an optionally substituted ortho-phenylene moiety;

m is 1 - 3;
n is 0 - 4;
p is 2 - 5;
q is 0 - 3;
r is I or 2; and
tisO-2;

the optional substitutent(s), if present, being selected from (C1-C6) alkyl, aryl which may be further substituted with one or more methyl or trifluoromethyl groups, hydroxy, (C1-C6) alkyloxky, (C1-C6)alkylsulphonyl, acyl, perfluroacyl, amino, (C1-C6) alkylamino, di(C1-C6)alkyl amino, amino alkylene, fluoro, chloro, bromo,trifluoromethyl, nitro, cyano, carbamoyl, carboxy and (C1-C6) alkyloxycarbonyl group and/or where two adjacent substituents are present, the two adjacent substituents may be linked so as to form a ring fused to the parent aryl or heteroaryl ring.

2. A compound as claimed in claim 1 wherein R1 is a nitrile group.

3. A compound as claimed in claim 2 wherein the stereocherrnstry of the nitrile group is as shown in formula 2.
(Formula Removed)

4. A compound as claimed in claim I or or 2 wherein the stereochemistry of the centre adjacent to the primary amine is of the S configuration as shown in formula 3.
(Formula Removed)
5. A compound as claimed in claim 4 wherein R' is a nitrile group and the stereochemistry of the nitrile group is as shown in formula 4.
(Formula Removed)
6. A compound as claimed in any preceding claim wherein m is 1.

7. A compound as claimed in any preceding claim wherein R2 and R3 are independently H or methyl.

8. A compound as claimed in any preceding Claim wherein m is 1 and R2 and R3 are both H.

9. A compound as claimed in any of Claims 1 to 7 wherein m is 1, 112 and R~ are both H, n is 0 and X3 is CO.

10. A compound as claimed in claim 9 wherein R4 is R6NH.
11. A compound as claimed in claim 1 wherein R' is H and X' is S.

12. The pharmaceutical composition for the treatment of at least one of type 2 diabetes, impaired glucose tolerance, growth hormone deficiency, polycystic ovary syndrome, and auto- immune and inflammatory diseases, the composition comprising at least one compound which is selected from derivatives of formula A, tautomers and stereolsomers thereof, and pharmaceutically acceptable salts of said
derivatives, tautomers and isomers, or which is as claimed in any of claims 1 to 11

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Patent Number

210805

Indian Patent Application Number

IN/PCT/2002/00868/DEL

PG Journal Number

42/2007

Publication Date

19-Oct-2007

Grant Date

08-Oct-2007

Date of Filing

02-Sep-2002

Name of Patentee

FERRING BV, a corporation organized and existing udner the laws of Netherlands

Applicant Address

POLARIS AVENUE 144, NL-2132, JX HOOFDDORP, THE NETHERLANDS.

Inventors:

#	Inventor's Name	Inventor's Address
1	EVANS DAVID MICHAEL	114 ADELAIDE ROAD, ST. DENYS, SOUTHAMPTON, SO17 2HX, U.K.
2	PITT GARY ROBERT WILLIAM	18 KINGFISHERS, SHIPTON-BELLINGER, TIDWORTH, HAMPSHIRE SP9 7US, U.K.

PCT International Classification Number

C07D 207/16

PCT International Application Number

PCT/GB01/01888

PCT International Filing date

2001-04-26

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0010183.2	2000-04-26	U.K.