Benzoheterocyclic compounds and use thereof

A compound of the formula (I):

• or a salt, prodrug or solvate thereof, wherein:
• X1 is CR11 or N;
• X2 is O, S or carbonyl;
• R1, R2, R4 and R5 are independently hydrogen, halo, nitro, azido, hydroxy, C1-C10 alkoxy, halo-substituted C1-C10 alkoxy, acyloxy, C1-C10 alkylthio, halo-substituted C1-C10 alkylthio, amino, carboxy, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl or C3-C10 cycloalkyl;
• R3 is hydrogen, halo, cyano, nitro, azido, hydroxy, C1-C10 alkoxy, halo-substituted C1-C10 alkoxy, acyloxy, mercapto, C1-C10 alkylthio, halo-substituted C1-C10 alkylthio, —SO2Ra, —SO2N(Rc)Rd, —N(Rc)Rd, —C(O)ORb, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl or C3-C10 cycloalkyl;
• Ra is C1-C10 alkyl or C6-C14 aryl;
• each Rb, Rc and Rd is independently hydrogen or C1-C10 alkyl;
• R6 is —C(O)OR7, —C(O)NR7R8, —C(O)N(R8)OR7, —C(O)R9 or —NHSO2R10;
• each R7 and R8 is independently hydrogen, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C3-C10 cycloalkyl, C3-C10 cycloalkyl C1-C10 alkyl or C1-C10 alkyl C3-C10 cycloalkyl;
• R9 is C1-C10 alkyl, C3-C10 cycloalkyl or C6-C14 aryl;
• R10 is C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C3-C10 cycloalkyl, C3-C10 cycloalkyl C1-C10 alkyl or C1-C10 alkyl C3-C10 cycloalkyl;
• and
• R11 is hydrogen, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C3-C10 cycloalkyl or C3-C10 cycloalkyl C1-C10 alkyl;
• wherein each C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl or C3-C10 cycloalkyl moiety may be unsubstituted or substituted with one or more groups independently selected from the group consisting of hydroxy, oxo, halo, cyano, nitro, trifluoromethyl, azido, amino, carboxy and mercapto;
• provided that if X1 is CH, X2 is O or S, R1 is methyl or chloro, R2 is hydrogen and R3 is iodo, then R6 is —NHSO2R10 or —C(O)N(R8)OR7 where R7 is C1-C10 alkyl substituted with at least one hydroxy group.