The present invention provides a diamine derivative or the like represented by the general formula (I):
wherein Q represents an oxygen atom or the like, RG represents a hydrogen atom or the like, RI represents
(wherein p and r may be the same or different, and each represents 0 or the like, RA represents a hydrogen atom or the like, and RB and Rc may be the same or different, and each represents a hydrogen atom or the like), RH represents a hydrogen atom or the like, and RJ represents:
(wherein q and s may be the same or different, and each represents 0 or the like, RD represents a hydrogen atom or the like, and RE and RF may be the same or different, and each represents a hydrogen atom or the like) or the like}, etc.
(wherein n is an integer of 0 to 10; R1 represents substituted or unsubstituted lower alkyl, substituted or unsubstituted lower alkoxy, substituted or unsubstituted cycloalkyl, substituted or unsubstituted lower alkoxycarbonyl, substituted or unsubstituted heterocyclic-alkyl, substituted or unsubstituted aryl, -CONR7R8, -NR9R10, etc.; R2 represents substituted or unsubstituted aryl or a substituted or unsubstituted heterocyclic group, etc.; R3 and R5 may be the same or different, each represent a hydrogen atom, substituted or unsubstituted lower alkyl, etc.; R4 and R6 may be the same or different, each represent a hydrogen atom, halogen, substituted or unsubstituted lower alkyl, etc.)
Provided are an Hsp90 family protein inhibitor comprising, as an active ingredient, a benzene derivative of formula (I) or a prodrug thereof or a pharmaceutically-acceptable salt thereof, etc.