Patent ID: 8106049

Claim:
A compound of formula (VI): as an isolated stereoisomer or a mixture of stereoisomers or as a pharmaceutically acceptable salt, wherein, R a is a bicyclic aryl group having 8 to 11 ring members, which may have 1 to 3 heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur; R b is a monocyclic aryl group having 5 to 7 ring members, which may have 1 to 2 heteroatoms selected from nitrogen, oxygen or sulfur, and aryl ring in the compound may have one or more substituents selected from a group consisting of halide, hydroxy, cyano, lower alkyl, and lower alkoxy groups; R c is a saturated or unsaturated C 1-6 alkyl, C 1-6 alkoxy, perfluoro C 1-6 alkyl group; and X 1 , X 2 , and X 3 may be the same or different and independently selected from hydrogen, hydroxyl, and halide.