Patent ID: 7803803

Claim:
A compound of formula (I), or a pharmaceutically acceptable salt, hydrate, ketal derivative or hemiketal derivative thereof, wherein: X is CH or N; one of R 1 and R 2 is H, and the other is selected from OH, OMe, OEt, O n Pr, O i Pr, O-cyclopropyl, O-cyclobutyl, SH, SMe, SEt, S n Pr, S i Pr, S-cyclopropyl, S-cyclobutyl, NH 2 , NHMe, NHEt, NH n Pr, NH i Pr, NH-cyclopropyl, NH-cyclobutyl, NMe 2 , N 3 , SOMe, SOEt, SO n Pr, SO i Pr, SO-cyclopropyl, SO-cyclobutyl, SO 2 Me, SO 2 Et, SO 2 n Pr, SO 2 i Pr, SO 2 -cyclopropyl, SO 2 -cyclobutyl, and R 3 is selected from tert-butylmethyl, iso-propylmethyl, sec-butyl, tert-butyl, cyclopentyl and cyclohexyl; R 4 is C 1-8 alkyl that is unsubstituted or substituted; or C 3-8 cycloalkyl that is unsubstituted or substituted.