Heterocycle amide T-type calcium channel antagonists

1. A compound of the formula I:

wherein:

A is pyridyl;

R 1 is selected from the group consisting of:

(1) C 1-6 alkyl, which is unsubstituted or substituted with halo, C 3-6 cycloalkyl or phenyl,

(2) C 3-6 cycloalkyl, which is unsubstituted or substituted with halo, C 3-6 cycloalkyl or phenyl, and

(3) phenyl, which is unsubstituted or substituted with one or more substituents selected from R 6 ;

R 2 and R 3 are independently selected from the group consisting of:

(1) hydrogen,

(2) halogen,

(3) C 1-6 alkyl, which is unsubstituted or substituted with halo, C 3-6 cycloalkyl or phenyl, and

(4) C 3-6 cycloalkyl, which is unsubstituted or substituted with halo, C 3-6 cycloalkyl or phenyl;

R 4 is 1,2,3-triazolyl, which is unsubstituted or substituted with one or more substituents selected from R 6 ;

R 5a , R 5b and R 5c are independently selected from the group consisting of:

(1) hydrogen,

(2) halogen,

(3) hydroxyl,

(4) C 1-6 alkyl, which is unsubstituted or substituted with halogen, hydroxyl, phenyl, —O—C 1-6 alkyl, —O—(CO)C 1-6 alkyl, or C 3-6 cycloalkyl,

(5) —O—C 1-6 alkyl, which is unsubstituted or substituted with halogen, hydroxyl, phenyl, —O—C 1-6 alkyl, —O—(CO)C 1-6 alkyl, or C 3-6 cycloalkyl, and

(6) —C 2-4 alkenyl;

R 6 is selected from the group consisting of:

(1) hydroxyl,

(2) halogen,

(3) C 1-6 alkyl, which is unsubstituted or substituted with halogen, hydroxyl, phenyl, —O—C 1-6 alkyl, —O—(CO)C 1-6 alkyl, —(CO)—O—C 1-6 alkyl, or C 3-6 cycloalkyl,

(4) —C 3-6 cycloalkyl, which is unsubstituted or substituted with halogen, hydroxyl, phenyl, —O—C 1-6 alkyl, —O—(CO)C 1-6 alkyl, or C 3-6 cycloalkyl,

(5) —O—C 1-6 alkyl,

(6) —O(C═O)—C 1-6 alkyl,

(7) —NH—C 1-6 alkyl,

(8) —NH 2 ,

(9) phenyl, which is unsubstituted or substituted with halogen, hydroxyl, phenyl, —O—C 1-6 alkyl, —O—(CO)C 1-6 alkyl, or C 3-6 cycloalkyl,

(11) —CO 2 H, and

(12) —CN;

or a pharmaceutically acceptable salt thereof.

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

(1) C 1-6 alkyl, and

(2) C 3-6 cycloalkyl.

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

(1) isopropyl,

(2) tert-butyl, and

(2) cyclopropyl.

4. The compound of claim 1 wherein R 2 is hydrogen and R 3 is hydrogen.

5. The compound of claim 1 wherein R 4 is triazolyl, which is unsubstituted or substituted with one or more substitutents selected from the group consisting of:

(1) halogen,

(2) hydroxyl, and

(3) C 1-6 alkyl, which is unsubstituted or substituted with halogen, hydroxyl, phenyl, —O—C 1-6 alkyl, —O—(CO)C 1-6 alkyl, or C 3-6 cycloalkyl.

6. The compound of claim 1 wherein R 5a , R 5b and R 5c are independently selected from the group consisting of:

(1) hydrogen,

(2) halogen,

(3) hydroxyl,

(4) C 1-6 alkyl, which is unsubstituted or substituted with halogen, hydroxyl, phenyl, —O—C 1-6 alkyl, —O—(CO)C 1-6 alkyl, or C 3-6 cycloalkyl, and

(5) —C 2-4 alkenyl.

7. The compound of claim 6 wherein R 5b is hydrogen, R 5c is hydrogen and R 5a is independently selected from the group consisting of:

(1) hydrogen,

(2) fluoro,

(3) chloro,

(4) bromo,

(5) hydroxyl,

(6) —CH 3 ,

(7) —CH 2 OH,

(8) —CH 2 CH 3 ,

(9) —CH 2 ═CH 2 , and

(10) —CH 2 CH 2 CH 3 .

8. A compound which is selected from the group consisting of:

N-[(S)-(5-bromopyridin-2-yl)(1-methyl-1H-1,2,3-triazol-4-yl)methyl]-2-(4-isopropylphenyl)acetamide;

2-(4-isopropylphenyl)-N-[(S)-(1-methyl-1H-1,2,3-triazol-4-yl)(5-propylpyridin-2-yl)methyl]acetamide;

N-{(S)-(1-methyl-1H-1,2,3-triazol-4-yl)[4-(2,2,2-trifluoroethoxy)phenyl]methyl}-2-[4-(propan-2-yl)phenyl]acetamide;

2-(4-tert-butylphenyl)-N-{(S)-[1-(4-methoxybenzyl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-butylphenyl)-N-{(S)-1H-1,2,3-triazol-4-yl[5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

Methyl 2-(4-{(S)-{[(4-tert-butylphenyl)acetyl]amino}[5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}-1H-1,2,3-triazol-1-yl)-2-methylpropanoate;

2-(4-tert-butylphenyl)-N-{(S)-[1-(2-hydroxy-1,1-dimethylethyl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-butylphenyl)-N-{(S)-[1-(2-fluoro-1,1-dimethylethyl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-Butylphenyl)-N-{(S)-[1-(2-hydroxyethyl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-Butylphenyl)-N-{(S)-[1-(2-fluoroethyl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

N-[(S)-(1-methyl-1H-1,2,3-triazol-4-yl)(5-propylpyridin-2-yl)methyl]-2-[4-(propan-2-yl)phenyl]acetamide;

N-{(S)-(1-methyl-1H-1,2,3-triazol-4-yl)[5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}-2-[4-(propan-2-yl)phenyl]acetamide;

2-(4-cyclopropylphenyl)-N-{(S)-(1-methyl-1H-1,2,3-triazol-4-yl)[5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-butylphenyl)-N-{(S)-(1-methyl-1H-1,2,3-triazol-4-yl)[5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-butylphenyl)-N-{(S)-1H-1,2,3-triazol-4-yl[5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-butylphenyl)-N-{(S)-[1-(2-hydroxyethyl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-cyclopropylphenyl)-N-{(S)-[1-(2-hydroxyethyl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-butylphenyl)-N-{(S)-[1-(2-fluoroethyl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide;

2-(4-tert-butylphenyl)-N-{(S)-[1-(1-fluoro-2-methylpropan-2-yl)-1H-1,2,3-triazol-4-yl][5-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}acetamide; and

2-(4-tert-butylphenyl)-N-{(S)-[5-(2,2,2-trifluoroethoxy)pyridin-2-yl][1-(2,2,2-trifluoroethyl)-1H-1,2,3-triazol-5-yl]methyl}acetamide;

or a pharmaceutically acceptable salt thereof.

9. A pharmaceutical composition which comprises an inert carrier and a compound of claim 1 or a pharmaceutically acceptable salt thereof.