Patent ID: 7414068

Claim:
A compound represented by following formula 1, stereoisomer thereof or pharmaceutically acceptable salt thereof: wherein, R 1 is Br, NO 2 , CN, OH, NH 2 , or OSO 2 R a provided that R a is C 1 -C 4 straight or branched alkyl; R 2 is CH 2 OR a or provided that R a is as defined in the above, R b and R c are independently C 1 -C 4 straight or branched alkyl; R 3 is OH or provided that R a is as defined in the above; R 4 is H, F, Cl, C 1 -C 3 straight or branched alkyl, OR a , CF 3 , OCF 3 , NO 2 , CH(OH)CH 3 , or SO 3 R a , provided that R a is as defined in the above; R 5 is H, OH 3 or OR a , provided that R a is as defined in the above; R 6 is H, C 1 -C 3 straight or branched alkyl; n is 0 or 1 and m is 1; * represent a chiral carbon.