Dipeptidyl peptidase inhibitors for the treatment of diabetes

1. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein:

X is NR 7 ;

Ar is selected from the group consisting of:

(1) phenyl and

(2) naphthyl,

wherein Ar is optionally substituted with 1–5 groups R 1 ;

R 1 is selected from the group consisting of:

(1) halogen,

(2) C 1-6 alkyl, which is linear or branched and is optionally substituted with 1–5 halogens,

(3) OC 1-6 alkyl, which is linear or branched and is optionally substituted with 1–5 halogens, and

(4) CN;

Each R 2 is independently selected from the group consisting of H, OH, halogen and C 1-6 alkyl, wherein C 1-6 alkyl is linear or branched and is optionally substituted with 1–5 halogens, wherein the two groups R 2 can optionally be joined to form a C 3-6 cycloalkyl, which is optionally substituted with 1–3 halogens;

Each R 3 is independently selected from the group consisting of H, halogen and C 1-6 alkyl, wherein C 1-6 alkyl is linear or branched and is optionally substituted with 1–5 halogens, wherein the two groups R 3 can optionally be joined to form a C 3-6 cycloalkyl, which is optionally substituted with 1–3 halogens;

Q is selected from the group consisting of:

(1) H,

(2) C 1-10 alkyl, which is linear or branched and is optionally substituted with 1–6 substituents independently selected from 0–5 halogens and 0–1 substituent selected from

(a) phenyl,

(b) naphthyl,

(c) a 5 or 6-membered heterocycle which may be saturated or unsaturated comprising 1–4 heteroatoms independently selected from N, S and O,

(d) an 8–10 membered bicyclic ring system which may be saturated or unsaturated which comprises (a) two fused heterocyclic rings, each heterocyclic ring having 1–4 heteroatoms independently selected from N, S and O, or (b) a phenyl ring fused to a 5- or 6-membered heterocycle having 1–3 heteroatoms selected from N, S and O,

(e) CO 2 H,

(f) CO 2 C 1-6 alkyl, and

(g) CONR 4 R 4

wherein said phenyl and naphthyl are optionally substituted with 1–5 substituents independently selected from C 1-6 alkyl, OC 1-6 alkyl, hydroxy and halogen, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens, and wherein said CO 2 C 1-6 alkyl is linear or branched, and wherein said 5 or 6-membered heterocycle and said 8–10 membered bicyclic ring system are optionally substituted with 1–5 substituents independently selected from C 1-6 alkyl, OC 1-6 alkyl, oxo, hydroxy and halogen, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens, and wherein said CO 2 C 1-6 alkyl is linear or branched;

(3) CN;

(4) Phenyl, which is optionally substituted with 1–5 substituents independently selected from C 1-6 alkyl, OC 1-6 alkyl, hydroxy and halogen, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens;

(5) Naphthyl, which is optionally substituted with 1–5 substituents independently selected from C 1-6 alkyl, OC 1-6 alkyl, hydroxy and halogen, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens,

(6) a 5 or 6-membered heterocycle which may be saturated or unsaturated comprising 1–4 heteroatoms independently selected from N, S and O, said heterocycle being optionally substituted with 1–5 substituents independently selected from oxo, hydroxy, C 1-6 alkyl, OC 1-6 alkyl and halogen, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens, and

(7) an 8–10 membered bicyclic ring system which may be saturated or unsaturated which comprises (a) two fused heterocyclic rings, each heterocyclic ring having 1–4 heteroatoms independently selected from N, S and O, or (b) a phenyl ring fused to a 5-or 6-membered heterocycle having 1–3 heteroatoms selected from N, S and O, wherein said bicyclic ring system is optionally substituted with 1–5 substituents independently selected from oxo, hydroxy, C 1-6 alky, OC 1-6 alkyl and halogen, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens;

R 4 is selected from

(1) H, and

(2) R 5 ;

R 5 is selected from the group consisting of phenyl, C 3-6 cycloalkyl and C 1-6 alkyl, wherein C 1-6 alkyl is linear or branched and is optionally substituted with 1–6 substituents independently selected from 0–5 halogens and 0–1 phenyl, wherein said optional phenyl substituent and said R 5 when R5 is phenyl or C 3-6 cycloalkyl are optionally substituted with 1–5 substituents independently selected from halogen, OH, C 1-6 alkyl, and OC 1-6 alkyl, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens; and

R 7 is selected from the group consisting of

(1) H,

(2) C 1- 6 alkyl which is linear or branched and is optionally substituted with 1–6 substituents independently selected from 0–5 halogens and 0–1 substituents selected from

(a) phenyl,

(b) naphthyl,

(c) a 5 or 6-membered heterocyclic ring which may be saturated or unsaturated comprising 1–4 heteroatoms independently selected from N, S and O,

(d) an 8–10 membered bicyclic ring system which may be saturated or unsaturated which comprises (a) two fused heterocyclic rings, each heterocyclic ring having 1–4 heteroatoms independently selected from N, S and O, or (b) a phenyl ring fused to a 5- or 6-membered heterocycle having 1–3 heteroatoms selected from N, S and O,

(e) C(═O)NR 4 R 4 , wherein said phenyl, naphthyl, and R 4 when R 4 is phenyl or C 3-6 cycloalkyl are optionally substituted with 1–5 substituents independently selected from halogen, OH, nitro, C 1-6 alkyl, OC 1-6 alkyl, and NHSO 2 C 1-6 alkyl, said C 1-6 alkyl, OC 1-6 alkyl and NHSO 2 C 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens, and wherein said 5-6-membered heterocycle and 8–10 membered bicyclic ring system are optionally substituted with 1–5 substituents independently selected from halogen, oxo, OH, C 1-6 alkyl, OC 1-6 alkyl, and NHSO 2 C 1-6 alkyl, said C 1-6 alkyl, OC 1-6 alkyl and NHSO 2 C 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens,

(3) Phenyl, which is optionally substituted with 1–5 substituents independently selected from halogen, OH, C 1-6 alkyl and OC 1-6 alkyl, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens,

(4) a 5 or 6-membered heterocycle which may be saturated or unsaturated comprising 1–4 heteroatoms independently selected from N, S and O, wherein said heterocycle is optionally substituted with 1–5 substituents independently selected from halogen, oxo, OH, C 1-6 alkyl and OC 1-6 alkyl, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens,

(5) an 8–10 membered bicyclic ring system which may be saturated or unsaturated which comprises (a) two fused heterocyclic rings, each heterocyclic ring having 1–4 heteroatoms selected from N, S and O, or (b) a 5- or 6-membered heterocycle having 1–3 heteroatoms selected from N, S and O fused to a phenyl ring, wherein said bicyclic ring system is optionally substituted with 1–5 substituents independently selected from halogen, oxo, OH, C 1-6 alkyl and OC 1-6 alkyl, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens,

(6) adamantyl, which is optionally substituted with 1–5 substituents independently selected from halogen, OH, C 1-6 alkyl and OC 1-6 alkyl, said C 1-6 alkYl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens;

(7) naphthyl, which is optionally substituted with 1–5 substituents independently selected from halogen, OH, C 1-6 alkyl and OC 1-6 alkyl, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens; and

(8) a 5–6 membered cycloalkyl fused to a phenyl ring, wherein said cycloalkyl may be saturated or unsaturated, wherein said cycloalkyl and fused phenyl ring are optionally substituted with 1–5 substituents independently selected from halogen, OH, C 1-6 alkyl and OC 1-6 alkyl, said C 1-6 alkyl and OC 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens;

with the proviso that X is not N−Me.

2. A compound of formula I as recited in claim 1 , wherein R 2 and R 3 are H.

3. A compound of formula I as recited in claim 1 , wherein Ar is phenyl, optionally substituted as in claim 1 .

4. A compound of formula I as recited in claim 1 , wherein Q is selected from the group consisting of phenyl and CH 2 phenyl, optionally substituted as in claim 1 .

5. A compound of formula I as recited in claim 1 , wherein X is NR 7 , and R 7 is CH 2 , which is substituted with 1 substituent selected from

(a) phenyl;

(b) naphthyl;

(c) a 5 or 6-membered heterocyclic ring which may be saturated or unsaturated comprising 1–4 heteroatoms independently selected from N, S and O;

(d) an 8–10 membered bicyclic ring system which may be saturated or unsaturated which comprises (a) two fused heterocyclic rings, each heterocyclic ring having 1–4 heteroatoms independently selected from N, S and O, or (b) a phenyl ring fused to a 5-or 6-membered heterocycle having 1–3 heteroatoms selected from N, S and O, and

(e) C(═O)NR 4 R 4 , wherein R 4 is as previously defined, and said phenyl, naphthyl, and R 4 when R 4 is phenyl or C 3-6 cycloalkyl are optionally substituted with 1–5 substituents independently selected from halogen, OH, C 1-6 alkyl, OC 1-6 alkyl, and NHSO 2 C 1-6 alkyl, said C 1-6 alkyl, OC 1-6 alkyl and NHSO 2 C 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens, and wherein said 5-6-membered heterocycle and 8–10 membered bicyclic ring system are optionally substituted with 1–5 substituents independently selected from halogen, oxo, OH, C 1-6 alkyl, OC 1-6 alkyl, and NHSO 2 C 1-6 alkyl, said C 1-6 alkyl, OC 1-6 alkyl and NHSO2C 1-6 alkyl being linear or branched and optionally substituted with 1–5 halogens.

6. A compound of Formula I as recited in claim 1 , wherein said 8–10 membered bicyclic ring system is selected from the group consisting of indole, indoline, benzofuran, benzothiophene, benzoxazole, benzisoxazole, benzothiazole, benzisothiazole, benzimidazole, benzimidazoline, quinoline, quinazoline, dihydroquinazoline, dihydroquinoline, isoquinoline, tetrahydroisoquinoline, and dihydroisoquinoline.

7. A compound of Formula I as recited in claim 1 , wherein said 5-or 6-membered heterocycle is selected from the group consisting of furan, thiophene, pyrrole, pyrroline, imidazole, imidazoline, pyrazole, pyrazoline, oxazole, oxazoline, isoxazole, isoxazoline, thiazole, thiazoline, isothiazole, isothiazoline, thiadiazole, thiadiazoline, tetrahydrofuran, tetrahydrothiophene, pyrrolidine, imidazolidine, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine, thiadiazolidine, sulfolane, pyran, dihydropyran, tetrahydropyran, imidazolidine, pyridine, pyridazine, pyrazine, pyrimidine, piperazine, piperidine, morpholine, tetrazole, triazole, triazolidine, and tetrazolidine.

8. A compound of Formula Ia:

or a pharmaceutically acceptable salt thereof, wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 7 , Q, X and Ar are as previously defined in claim 1 ; with the proviso that X is not N-Me.

9. A compound of Formula Ib:

or a pharmaceutically acceptable salt thereof, wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 7 , Q, X and Ar are as previously defined in claim 1 ; with the proviso that X is not N-Me.

10. A pharmaceutical composition comprising a compound of claim 1 and a pharmaceutically acceptable carrier.

11. A method for treating non-insulin dependent (Type 2) diabetes mellitus in a mammalian patient in need of such treatment which comprises administering to said patient a therapeutically effective amount of a compound of claim 1 .