1,2,4-Oxadiazole derivatives as dipeptidyl peptidase-IV inhibitors for the treatment or prevention of diabetes

1. A compound of the formula I:

or a pharmaceutically acceptable salt thereof; wherein

each n is independently 0, 1, or 2;

m and p are each independently 0 or 1;

X is CH 2 , S, CHF, or CF 2 ;

W and Z are each independently CH 2 , CHF, or CF 2 ;

R 1 is hydrogen or cyano;

R 3 is aryl or heteroaryl, wherein aryl and heteroaryl are unsubstituted or substituted with one to five R 4 substituents;

R 2 is selected from the group consisting of

hydrogen,

C 1-10 alkyl, wherein alkyl is unsubstituted or substituted with one to five substituents independently selected from halogen or hydroxy,

C 2-10 alkenyl, wherein alkenyl is unsubstituted or substituted with one to five substituents independently selected from halogen or hydroxy,

(CH 2 ) n -aryl, wherein aryl is unsubstituted or substituted with one to five substituents independently selected hydroxy, halogen, CO 2 H, C 1-6 alkyloxycarbonyl, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

(CH 2 ) n -heteroaryl, wherein heteroaryl is unsubstituted or substituted with one to three substituents independently selected from hydroxy, halogen, CO 2 H, C 1-6 alkyloxycarbonyl, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

(CH 2 ) n -heterocyclyl, wherein heterocyclyl is unsubstituted or substituted with one to three substituents independently selected from oxo, hydroxy, halogen, CO 2 H, C 1-6 alkyloxycarbonyl, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

(CH 2 ) n —C 3-6 cycloalkyl, wherein cycloalkyl is unsubstituted or substituted with one to three substituents independently selected from halogen, hydroxy, CO 2 H, C 1-6 alkyloxycarbonyl, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

(CH 2 ) n COOH,

(CH 2 ) n COOC 1-6 alkyl,

(CH 2 ) n CONR 5 R 6 , wherein R 5 and R 6 are independently selected from the group consisting of hydrogen, tetrazolyl, thiazolyl, (CH 2 ) n -phenyl, (CH 2 ) n —C 3-6 cycloalkyl, and C 1-6 alkyl, wherein alkyl is unsubstituted or substituted with one to five substituents independently selected from halogen and hydroxy and wherein phenyl and cycloalkyl are unsubstituted or substituted with one to five substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens;

or wherein R 5 and R 6 together with the nitrogen atom to which they are attached form a heterocyclic ring selected from azetidine, pyrrolidine, piperidine, piperazine, and morpholine wherein said heterocyclic ring is unsubstituted or substituted with one to three substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens; and

wherein any methylene (CH 2 ) carbon atom in R 2 is unsubstituted or substituted with one to two groups independently selected from halogen, hydroxy, and C 1-4 alkyl unsubstituted or substituted with one to five halogens;

each R 4 is independently selected from the group consisting of

halogen,

cyano,

hydroxy,

C 1-6 alkyl, wherein alkyl is unsubstituted or substituted with one to five halogens,

C 1-6 alkoxy, wherein alkoxy is unsubstituted or substituted with one to five halogens,

(CH 2 ) n —NR 5 R 6 ,

(CH 2 ) n —CONR 5 R 6 ,

(CH 2 ) n —OCONR 5 R 6 ,

(CH 2 ) n —SO 2 NR 5 R 6 ,

(CH 2 ) n —SO 2 R 8 ,

(CH 2 ) n —NR 7 SO 2 R 8 ,

(CH 2 ) n —NR 7 CONR 5 R 6 ,

(CH 2 ) n —NR 7 COR 7 ,

(CH 2 ) n —NR 7 CO 2 R 8 ,

(CH 2 ) n —COOH,

(CH 2 ) n —COOC 1-6 alkyl,

(CH 2 ) n -aryl, wherein aryl is unsubstituted or substituted with one to five substituents independently selected from halogen, hydroxy, CO 2 H, C 1-6 alkyloxycarbonyl, C 1-6 alkyl, C 3-6 cycloalkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

(CH 2 ) n -heteroaryl, wherein heteroaryl is unsubstituted or substituted with one to three substituents independently selected from hydroxy, halogen, CO 2 H, C 1-6 alkyloxycarbonyl, C 1-6 alkyl, C 3-6 cycloalkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

(CH 2 ) n -heterocyclyl, wherein heterocyclyl is unsubstituted or substituted with one to three substituents independently selected from oxo, hydroxy, halogen, CO 2 H, C 1-6 alkyloxycarbonyl, C 1-6 alkyl, C 3-6 cycloalkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

(CH 2 ) n —C 3-6 cycloalkyl, wherein cycloalkyl is unsubstituted or substituted with one to three substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

wherein any methylene (CH 2 ) carbon atom in R 4 is unsubstituted or substituted with one to two groups independently selected from halogen, hydroxy, and C 1-4 alkyl unsubstituted or substituted with one to five halogens;

R 5 and R 6 are each independently selected from the group consisting of hydrogen, tetrazolyl, thiazolyl, (CH 2 ) n -phenyl, (CH 2 ) n —C 3-6 cycloalkyl, and C 1-6 alkyl, wherein alkyl is unsubstituted or substituted with one to five substituents independently selected from halogen and hydroxy and wherein phenyl and cycloalkyl are unsubstituted or substituted with one to five substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens;

or R 5 and R 6 together with the nitrogen atom to which they are attached form a heterocyclic ring selected from azetidine, pyrrolidine, piperidine, piperazine, and morpholine wherein said heterocyclic ring is unsubstituted or substituted with one to three substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens;

each R 8 is independently selected from the group consisting of tetrazolyl, thiazolyl, (CH 2 ) n -phenyl, (CH 2 ) n —C 3-6 cycloalkyl, and C 1-6 alkyl, wherein alkyl is unsubstituted or substituted with one to five halogens and wherein phenyl and cycloalkyl are unsubstituted or substituted with one to five substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens, and wherein any methylene (CH 2 ) carbon atom in R 8 is unsubstituted or substituted with one to two groups independently selected from halogen, hydroxy, and C 1-4 alkyl unsubstituted or substituted with one to five halogens; and

each R 7 is hydrogen or R 8 .

2. The compound of claim 1 wherein the carbon atom marked with an * has the stereochemical configuration as depicted in formula Ia:

3. The compound of claim 2 wherein the carbon atom attached to R 1 marked with an ** has the stereochemical configuration as depicted in the formula Ib:

4. The compound of claim 1 wherein m is 1 and p is 0 as depicted in formula Ic:

5. The compound of claim 4 wherein the carbon atom marked with an * and the carbon atom marked with an ** have the stereochemical configurations as depicted in the formula Id:

6. The compound of claim 5 wherein R 1 is hydrogen; W is CH 2 ; and X is CH 2 , CHF or CF 2 .

7. The compound of claim 1 wherein R 1 is hydrogen, X is CHF, and m and p are 0 as depicted in the formula Ie:

8. The compound of claim 7 wherein the carbon atom marked with an * has the stereochemical configuration as depicted in the formula If:

9. The compound of claim 1 wherein R 1 is hydrogen, and m and p are 1 as depicted in formula Ig:

10. The compound of claim 9 wherein the carbon atom marked with an * has the stereochemical configuration as depicted in the formula Ih:

11. The compound of claim 10 wherein W and Z are CH 2 and X is CHF or CF 2 .

12. The compound of claim 1 wherein R 2 is selected from the group consisting of:

C 1-6 alkyl, wherein alkyl is unsubstituted or substituted with one to five substituents independently selected from halogen or hydroxy,

C 2-6 alkenyl, wherein alkenyl is unsubstituted or substituted with one to five substituents independently selected from halogen or hydroxy,

(CH 2 ) n —C 3-6 cycloalkyl, wherein cycloalkyl is unsubstituted or substituted with one to three substituents independently selected from halogen, hydroxy, CO 2 H, C 1-6 alkyloxycarbonyl, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens,

(CH 2 ) n COOH,

(CH 2 ) n COOC 1-6 alkyl,

(CH 2 ) n CONR 5 R 6 , wherein R 5 and R 6 are independently selected from the group consisting of hydrogen, tetrazolyl, thiazolyl, (CH 2 ) n -phenyl, (CH 2 ) n —C 3-6 cycloalkyl, and C 1-6 alkyl, wherein alkyl is unsubstituted or substituted with one to five substituents independently selected from halogen and hydroxy and wherein phenyl and cycloalkyl are unsubstituted or substituted with one to five substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens;

or wherein R 5 and R 6 together with the nitrogen atom to which they are attached form a heterocyclic ring selected from azetidine, pyrrolidine, piperidine, piperazine, and morpholine wherein said heterocyclic ring is unsubstituted or substituted with one to five substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens; and

wherein any methylene (CH 2 ) carbon atom in R 2 is unsubstituted or substituted with one to two groups independently selected from halogen, hydroxy, and C 1-4 alkyl unsubstituted or substituted with one to five halogens.

13. The compound of claim 12 wherein R 2 is selected from the group consisting of:

C 1-3 alkyl, wherein alkyl is unsubstituted or substituted with one to five substituents independently selected from halogen or hydroxy,

CH 2 —C 3-6 cycloalkyl,

COOH,

COOC 1-6 alkyl,

CONR 5 R 6 , wherein R 5 and R 6 are independently selected from the group consisting of hydrogen, tetrazolyl, thiazolyl, (CH 2 ) n -phenyl, (CH 2 ) n —C 3-6 cycloalkyl, and C 1-6 alkyl, wherein alkyl is unsubstituted or substituted with one to five substituents independently selected from halogen and hydroxy and wherein phenyl and cycloalkyl are unsubstituted or substituted with one to five substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens;

or wherein R 5 and R 6 together with the nitrogen atom to which they are attached form a heterocyclic ring selected from azetidine, pyrrolidine, piperidine, piperazine, and morpholine wherein said heterocyclic ring is unsubstituted or substituted with one to five substituents independently selected from halogen, hydroxy, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens.

14. The compound of claim 1 of structural formula Ii:

wherein X is CH 2 , S, CHF, or CF 2 ;

W and Z are each independently CH 2 , CHF, or CF 2 ;

R 3 is aryl, unsubstituted or substituted with one to three R 4 substituents;

R 2 is selected from the group consisting of:

methyl,

ethyl,

propyl,

2-methylpropyl,

propenyl,

CH 2 -cyclopropyl,

CH 2 -(1-methylcyclopropyl),

2-hydroxyethyl, and

2,2-difluoropropyl; and

each R 4 is independently selected from the group consisting of:

halogen,

C 1-6 alkyl, wherein alkyl is unsubstituted or substituted with one to five halogens,

C 1-6 alkoxy, wherein alkoxy is unsubstituted or substituted with one to five halogens,

SO 2 NR 5 R 6 ,

SO 2 R 8 ,

NR 7 SO 2 R 8 , and

heteroaryl, wherein heteroaryl is unsubstituted or substituted with one to three substituents independently selected from hydroxy, halogen, CO 2 H,

C 1-6 alkyloxycarbonyl, C 1-6 alkyl, and C 1-6 alkoxy, wherein alkyl and alkoxy are unsubstituted or substituted with one to five halogens.

15. The compound of claim 14 wherein R 3 is selected from the group consisting of:

2-(trifluoromethoxy)phenyl,

4-(trifluoromethoxy)phenyl,

3,5-dichlorophenyl,

2,4-dichlorophenyl,

2,4-difluorophenyl,

3,5-difluorophenyl,

2-fluorophenyl,

4-fluorophenyl,

2-chlorophenyl,

4-chlorophenyl,

2-(trifluoromethyl)phenyl,

3-(trifluoromethyl)phenyl,

4-(trifluoromethyl)phenyl,

2-fluoro-4-(trifluoromethyl)phenyl,

2-chloro-4-(trifluoromethyl)phenyl,

2,6-dichloro-4-(trifluoromethyl)phenyl,

2-chloro-4-fluorophenyl,

2-chloro-4-bromophenyl,

4-(methylsulfonyl)phenyl,

4-[(trifluoromethyl)sulfonyl]phenyl,

4-(aminosulfonyl)phenyl,

4-[cyclopropylamino)sulfonyl]phenyl,

4-[(methylsulfonyl)amino]phenyl,

2-fluoro-4-(methylsulfonyl)phenyl,

2-chloro-4-(methylsulfonyl)phenyl,

2-fluoro-4-[(methylsulfonyl)amino]phenyl,

2-chloro-4-[(methylsulfonyl)amino]phenyl,

2-fluoro-4-(aminosulfonyl)phenyl,

2-chloro-4-(aminosulfonyl)phenyl,

2-chloro-4-(tetrazol-1-yl)phenyl, and

2-chloro-4-(tetrazol-5-yl)phenyl.

16. The compound of claim 1 which is selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.

17. A pharmaceutical composition which comprises a compound of claim 1 and a pharmaceutically acceptable carrier.

18. A method for treating diabetes in a mammal in need thereof which comprises the administration to the mammal of a therapeutically effective amount of a compound of claim 1 .

19. A method for treating non-insulin dependent (Type 2) diabetes in a mammal in need thereof which comprises the administration to the mammal of a therapeutically effective amount of a compound of claim 1 .

20. A method for treating hyperglycemia in a mammal in need thereof which comprises the administration to the mammal of a therapeutically effective amount of a compound of claim 1 .