Patent ID: 7718681

Claim:
A compound represented by the following formula 1 or its pharmaceutically acceptable salt thereof: wherein X is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, a halogen atom, C 1 -C 4 alkoxy, unsubstituted or substituted with C 1 -C 4 alkylcarboxyl, C 1 -C 4 haloalkoxy, C 3 -C 4 alkenyloxy, C 2 -C 4 acyl, C 3 -C 10 cycloalkylalkoxy, C 3 -C 10 cycloalkyloxy, hydroxy, cyano or nitro; Y is hydrogen, C 1 -C 4 alkyl, a halogen atom, C 1 -C 4 alkoxy, C 3 -C 4 alkenyloxy, C 2 -C 4 acyl, cyano or nitro; n is an integer of from 1 to 5; and R is hydrogen, C 1 -C 4 alkyl, C 2 -C 4 alkenyl, C 3 -C 4 alkynyl, C 1 -C 4 haloalkyl, C 2 -C 4 alkoxyalkyl or benzyl.