Patent ID: 8501803

Claim:
A compound of Formula (I) or its pharmaceutically acceptable salt: wherein R 1 is a single substituent or a multi substituent group; when R 1 is the single substituent group, R 1 is a hydroxyl group; and when R 1 is the multi substituent group, one of the substituent groups is a hydroxyl group, and the rest of the substituent groups are selected from an amino group, a nitro group, a cyano group, an alkyl group containing C 1 -C 6 carbons, or an alkenyl group containing C 2 -C 6 carbons; wherein R 2 is halogen, a hydroxyl group, an alkoxy group containing C 1 -C 4 carbons, an amide group containing C 1 -C 4 carbons, a carboxyl group, or an aldehyde group.