Fluorescent compounds that bind to histone deacetylase

A compound represented by the following structural Formula

• wherein A is aryl, heteroaryl or H, optionally substituted with halo, methyl, methoxy, amino, hydroxyl or halomethyl;
• R1 and R2 are independently selected from H, OH, halo, NH2, C1-C4 alkyl, or C1-C4 alkoxy;
• R3 is independently selected from H, OH, NH2, nitro, CN, amide, carboxyl, C1-C7 alkoxy, C1-C7 alkyl, C1-C7 haloalkyl, C1-C7 haloalkyloxy, C1-C7 hydroxyalkyl, C1-C7 alkenyl, C1-C7 alkyl-C(═O)O—, C1-C7 alkyl-C(═O)—, C1-C7 alkynyl, halo, hydroxyalkoxy, C1-C7 alkyl-NHSO2—, C1-C7 alkyl-SO2NH—, C1-C7 alkylsulfonyl, C1-C7 alkylamino or di(C1-C7)alkylamino;
• R4 is selected from —NR6R7;
• R5 is independently selected from H, OH, NH2, nitro, CN, amide, carboxyl, C1-C2 alkoxy, C1-C2 alkyl, C1-C2 haloalkyl, C1-C2 haloalkyloxy, C1-C2 hydroxyalkyl, C1-C2 alkenyl, C1-C2 alkyl-C(═O)O—, C1-C2 alkyl-C(═O)—, C1-C2 alkynyl, halo, hydroxyalkoxy, C1-C2 alkyl-NHSO2—, C1-C2 alkyl-SO2NH—, C1-C2 alkylsulfonyl, C1-C2 alkylamino or di(C1-C2)alkylamino;
• R6 is independently selected from H or C1-C4 alkyl;
• R7 is selected from —(CRa2)sC(O)(CRa2)qR12, or —(CRa2)C(O)O(CRa2)qR12;
• R12 is selected from C1-C4 alkyl, C3-C6 cycloalkyl, heteroaryl, aryl or heterocyclic, wherein the alkyl, cycloalkyl, heteroaryl, heterocyclic or aryl is attached to a fluorophore through a linker, and optionally substituted OH, NH2, nitro, CN, amide, carboxyl, C1-C7 alkoxy, C1-C7 alkyl, C1-C7 haloalkyl, C1-C7 haloalkyloxy, C1-C7 hydroxyalkyl, C1-C7 alkenyl, C1-C7 alkyl-C(═O)O—, C1-C7 alkyl-C(═O)—, C1-C7 alkynyl, halo, hydroxyalkoxy, C1-C7 alkyl-NHSO2—, C1-C7 alkyl-SO2NH—, C1-C7 alkylsulfonyl, C1-C7 alkylamino or di(C1-C7)alkylamino, aryl, heterocyclic or cycloalkyl;
• Ra is independently selected from H or C1-C4 alkyl;
• p is 1, 2, 3 or 4;
• s and q are independently 0, 1, 2, 3, or 4;
• L1 is (CH2)r, ethenyl or cyclopropyl, wherein r is 0, 1 or 2;
• X is OH or NH2;
• Z is C or N;
• or a stereoisomer or pharmaceutically acceptable salt thereof.