Patent ID: 8541595

Claim:
A compound of the formula: wherein: R 1 is hydrogen or C 1-6 alkyl; R 2 is hydrogen or C 1-6 alkyl; R 3a is selected from the group consisting of: (1) hydrogen, (2) halogen, (3) —CN, and (4) C 1-6 alkyl; R 4 is selected from the group consisting of: (1) —CH 2 CH 2 —(C═O)-heterocycle, where the heterocycle is unsubstituted or substituted with one or more substituents selected from R 13 , and (2) —CH 2 CH 2 —(C═O)—NR 15 R 16 , where R 15 and R 16 are independently selected from hydrogen and —C 1-6 alkyl, which is unsubstituted or substituted with phenyl; R 13 is selected from the group consisting of: (1) halogen, (2) hydroxyl, (3) —(C═O) m —O n —C 1-6 alkyl, where m is 0 or 1, n is 0 or 1 (wherein if m is 0 or n is 0, a bond is present) and where the alkyl is unsubstituted or substituted with one or more substituents selected from R 14 , (4) —O n —(C 1-3 )perfluoroalkyl, (5) —(C═O) m —O n C 3-6 cycloalkyl, where the cycloalkyl is unsubstituted or substituted with one or more substituents selected from R 14 , (6) —(C═O) m —C 2-4 alkenyl, where the alkenyl is unsubstituted or substituted with one or more substituents selected from R 14 , (7) —(C═O) m —C 2-4 alkynyl, where the alkenyl is unsubstituted or substituted with one or more substituents selected from R 14 , (8) —(C═O) m —O n -phenyl or —(C═O) m —O n -napthyl, where the phenyl or is unsubstituted or substituted with one or more substituents selected from R 14 , (9) —(C═O) m —O n -heterocycle, where the heterocycle is unsubstituted or substituted with one or more substituents selected from R 14 , (10) —(C═O) m —NR 15 R 16 , (11) —S(O) 2 —NR 15 R 16 , (12) —S(O) q —R 17 , where q is 0, 1 or 2 and where R 17 is —C 1-6 alkyl, which is unsubstituted or substituted with phenyl; (13) —CO 2 H (14) —CN, and (15) —NO 2 ; R 14 is selected from the group consisting of: (1) hydroxyl, (2) halogen, (3) C 1-6 alkyl, (4) —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) phenyl, (9) heterocycle, (10) —CO 2 H, and (11) —CN; or a pharmaceutically acceptable salt thereof.