| abstract |
A compound of formula (I): or a stereoisomer, tautomer or pharmaceutically acceptable salt thereof, wherein R a is selected from the group consisting of (1) hydrogen, (2) halogen, (3) hydroxyl, (4) C 1 -C 6 alkoxy, (5) thiol, (6) C1-C6 alkylthiol, (7) substituted or unsubstituted C1-C6 alkyl, (8) amino or substituted amino, (9) substituted or unsubstituted aryl, (10) substituted or unsubstituted heteroaryl, and ( 11) substituted or unsubstituted heterocyclyl; R is selected from the group consisting of (1) hydrogen, (2) substituted or unsubstituted C1-C6 alkyl, (3) substituted or unsubstituted C2-C6 alkenyl, (4) substituted or unsubstituted C2-C6 alkynyl, (5) substituted or unsubstituted C3-C7 cycloalkyl, (6) substituted or unsubstituted C5-C7 cycloalkenyl, (7) substituted or unsubstituted aryl, (8) substituted or unsubstituted heteroaryl, and (9) substituted or unsubstituted heterocyclyl; Rb is selected from the group consisting of (1) substituted or unsubstituted C3-C7 cycloalkyl, (2) substituted or unsubstituted C5-C7 cycloalkenyl, (3) substituted or unsubstituted aryl, (4) substituted or unsubstituted heteroaryl, and (5) substituted or unsubstituted heterocyclyl; and provided that when Ra is amino, then Rb is not phenyl, 4-alkyl-phenyl, 4-alkoxy-phenyl or 4-halo-phenyl. The patent contains another 46 patent claims. |