Patent ID: 8785477

Claim:
A compound according to formula (I) or optical isomers, crystal forms, pharmaceutically acceptable inorganic or organic salts, hydrates or solvates thereof: wherein, X is selected from the group consisting of: (1) —C 1 -C 3 alkylidene; (2) —C(O)—; (3) —S(O) 2 —; (4) —C(O)O—; and (5) —C(O)NR 1 —; R is selected from the group consisting of: (1) H; (2) C 1 -C 6 alkyl, which is unsubstituted or substituted by one to three substituents selected from the following group: fluorine, chlorine or hydroxyl; (3) C 3 -C 6 cycloalkyl, which is unsubstituted or substituted by one to two substituents selected from the following group: C 1 -C 3 alkyl, fluorine, chlorine, hydroxyl, cyano, C(O)NH 2 ; (4) Phenyl, which is unsubstituted or substituted by one to three substituents selected from the followings: C 1 -C 3 alkyl, fluorine, chlorine, cyano, S(O) 2 R 2 ; and (5) 6-membered heterocycle containing one to two atoms independently selected from N atom, above-mentioned 6-membered heterocycle is unsubstituted or substituted by one to three substituents selected from the followings: C 1 -C 3 alkyl, fluorine, chlorine, cyano, S(O) 2 R 2 ; wherein, R 1 is H or C 1 -C 3 alkyl; R 2 is C 1 -C 3 alkyl.