Patent ID: 7884099

Claim:
A compound of structural formula (I): or a pharmaceutically acceptable salt thereof, wherein: X 1 is NH, NR 4 , O or S; X 2 is N or CR 5 ; L is a bond, or a linker group selected from one or a combination of two to three of the following groups: 1) (C 1 -C 6 )alkylene, 2) (C 3 -C 8 )cycloalkylene, 3) arylene, 4) heteroarylene, 5) heterocycloalkylene containing 1 to 3 heteroatoms, 6) —C(═O)—, 7) —C(═N—O—R 6 )—, 8) —C═N—, 9) —O—, 10) —S(O) n —, wherein n is number between 0 and 2, 11) —N(R 7 )—, wherein the carbon or nitrogen atoms of the linker “L” group are optionally substituted by 1 to 3 substituents selected from (C 1 -C 6 )alkyl, substituted (C 1 -C 6 )alkyl, amino, (C 1 -C 6 )alkylamino, di(C 1 -C 6 )alkylamino, hydroxyl, (C 1 -C 6 )alkoxy, and heterocycloalkyl group; Q is N or CR 8 ; Y and Z are independently selected from C or N; R 1 is H or acetyl group; R 2 , R 4 , R 5 , R 6 , R 7 are independently a group selected from hydrogen, (C 1 -C 6 )alkyl, (C 3 -C 7 )cycloalkyl, aryl, heteroaryl, and heterocycloalkyl groups that are all optionally substituted; R 3 is H, —OH or —SH; and R 8 is H, F, Cl, CN, CH 3 ,'OCH 3 , OCHF 2 or CF 3 .