Patent ID: 7138543

Claim:
A compound of formula Ib or a pharmaceutically acceptable equivalent, wherein: A 1 , A 2 , A 3 and A 4 are independently hydrogen, C 1 –C 9 alkyl, C 2 –C 9 alkenyl, C 2 –C 9 alkynyl, aryl, heteroaryl, carbocycle, heterocycle, halo, hydroxy, sulfhydryl, nitro, amino, cyano, isocyano, thiocyano, isothiocyano, formamido, thioformamido, sulfo, sulfino, C 1 –C 9 alkylsulfonyl, C 1 –C 9 alkoxy, C 2 –C 9 alkenoxy, phenoxy, or benzyloxy, wherein said alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocycle, heterocycle, alkoxy, alkenoxy, phenoxy, and benzyloxy are independently unsubstituted or substituted with one or more substituent(s), wherein if A 1 is chloro, fluoro, amino, or thiolmethyl, then A 2 , A 3 , and A 4 may not all be hydrogen, and wherein at least one of A 1 , A 2 , A 3 , and A 4 is not hydrogen.