Patent ID: 8053581

Claim:
A compound of formula (Ia): wherein, R1 is phenyl-C 1 -C 6 alkyl or C 3 -C 10 cycloalkyl-C 1 -C 6 alkyl, wherein phenyl is unsubstituted or substituted with one, two or three substituents independently selected from halogen, nitro, hydroxyl, amino, cyano, C 1 -C 6 alkyl, C 1 -C 6 alkoxy and C 1-6 haloalkyl; and wherein said alkyl in said alkyl in said phenyl-C 1 -C 6 alkyl or C 3 -C 10 cycloalkyl-C 1 -C 6 alkyl and said cycloalkyl in said C 3 -C 10 cycloalkyl-C 1 -C 6 alkyl may be optionally substituted with hydroxyl, oxo or amino, or optionally spaced by —O—, —S—, —NH—, —COO—, or —CONH—; each R2 is independently hydrogen, hydroxyl, halogen, C 1 -C 6 alkoxy, C 1 -C 6 alkyl, C 1-6 haloalkyl, amino, nitro, cyano or alkylacyl; R4 is hydrogen, benzoyl or phenylsulfonyl; wherein the phenyl in benzoyl and phenylsulfonyl is optionally substituted with one or two substituents independently selected from hydroxyl, halogen, nitro, amino, cyano, C 1 -C 6 alkyl, C 1 -C 6 alkoxy and C 1-6 haloalkyl; each R5 is independently selected from hydrogen, hydroxyl, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1-6 haloalkyl, amino, halogen, nitro, cyano and alkylacyl; X is —(C═O)—; n is 0, 1, 2 or 3; and m is 0, 1, 2, 3 or 4, or pharmaceutically acceptable salt thereof.