Patent ID: 7732603

Claim:
A compound of the formula wherein X is oxygen or H 2 ; R 1a is a monocyclic or bicyclic aryl or, monocyclic heteroaryl; R 1b is hydrogen, alkyl, or aralkyl; R 2 is R 6 —(CHR 7 ) p — in which R 6 is alkyl, cycloalkyl, aryl or monocyclic heterocyclyl; R 7 is hydrogen, alkyl, aryl, monocyclic heteroaryl or aralkyl; p is zero or an integer from 1 to 4; R 3 and R 4 are independently hydrogen; or R 5 is hydrogen; in which each alkyl is optionally substituted with halo, hydroxy, cycloalkyl, alkanoyl, alkoxy, alkyloxyalkoxy, alkanoyloxy, amino, alkylamino, dialkylamino, acylamino, carbamoyl, thiol, alkylthio, alkylthiono, sulfonyl, sulfonamido, sulfamoyl, nitro, cyano, carboxy, alkoxycarbonyl, aryl, alkenyl, alkynyl, araloxy, guanidino and monocyclic heterocyclyl; and each aryl is optionally substituted with alkyl, trifluoromethyl, cycloalkyl, halo, hydroxy, alkoxy, acyl, alkanoyloxy, aryloxy, amino, thiol, alkylthio, arylthio, nitro, cyano, carboxy, alkoxycarbonyl, carbamoyl, alkylthiono, sulfonyl, sulfonamido and monocyclic heterocyclyl; and each cycloalkyl is optionally substituted with alkyl, halo, oxo, hydroxy, alkoxy, alkanoyl, acylamino, carbamoyl, alkylamino, dialkylamino, thiol, alkylthio, nitro, cyano, carboxy, alkoxycarbonyl, sulfonyl, sulfonamido, sulfamoyl and monocyclic heterocyclyl; and each heterocyclyl and heteroaryl are independently optionally substituted with alkyl, hydroxy, halo, oxo, amino, alkylamino, dialkylamino, alkoxy, cycloalkyl, carboxy, alkoxycarbonyl, mercapto, cyano, nitro, sulfamoyl, sulfonamido, aryl, alkanoyloxy, aroyloxy, arylthio, aryloxy, alkylthio, formyl, carbamoyl, aryl and arylalkyl; and each heteroaryl is selected from 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-thienyl, 3-thienyl, 2-furyl or 3-furyl; and each heterocyclyl is selected from morpholinyl, 2-thienyl, 3-thienyl, piperidinyl, 2-furyl, 3-furyl, 2-pyridyl, 3-pyridyl or 4-pyridyl; or a pharmaceutically acceptable salt thereof; or a diastereomer thereof; or a mixture of diastereomers thereof; or an optical isomer thereof; or a mixture of optical isomers thereof.