Hydrazone derivatives for the treatment of cancer

A compound of formula (I):

• or a salt thereof, wherein:
• the ring A is a fused benzo or heteroaryl ring;
• X is S, O, —CH═CH—, or N—Ra;
• HET is selected from the group consisting of:
• wherein HET is optionally substituted with one or more groups R1 independently selected from halo, cyano, hydroxy, nitro, —N(Ra)2, carboxy, phenyl, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkoxy, (C1-C6)alkanoyl, (C1-C6)alkoxycarbonyl, (C2-C6)alkanoyloxy,
• wherein any phenyl, (C1-C6)alkyl, (C1-C6)alkoxy, (C2-C6)alkenyl, (C2-C6)alkynyl, and (C3—C6)cycloalkyl, is optionally substituted with one or more groups independently selected from halo, azido, cyano, hydroxy, nitro, —N(Rb)2, carboxy, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, (C1-C6)alkoxycarbonyl, (C2-C6)alkanoyloxy, and (C1-C6)alkoxy that is optionally substituted with carboxy;
• each R2 is independently selected from the group consisting of H, phenyl, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, and (C3-C6)cycloalkyl, wherein any phenyl, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, and (C3-C6)cycloalkyl, is optionally substituted with one or more groups independently selected from halo, —N(Rc)2, (C3-C6)cycloalkyl, (C1-C6)alkoxy, and (C2-C6)alkanoyloxy;
• n is 0, 1, 2, 3, or 4;
• each R3 is independently selected from halo, cyano, hydroxy, nitro, —N(Rd)2, carboxy, phenyl, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkoxy, (C1-C6)alkanoyl, (C1-C6)alkoxycarbonyl, and (C2-C6)alkanoyloxy, wherein any phenyl, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkoxy, and (C3-C6)cycloalkyl, is optionally substituted with one or more groups independently selected from halo, cyano, hydroxy, nitro, —N(Rc)2, carboxy, (C3-C6)cycloalkyl, (C1-C6)alkoxy, (C1-C6)alkanoyl, (C1-C6)alkoxycarbonyl, and (C2-C6)alkanoyloxy;
• Ra is selected from the group consisting of H, (C1-C6)alkyl, (C2-C6)alkenyl, (C2—C)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, wherein any (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, is optionally substituted with one or more groups independently selected from halo, (C3-C6)cycloalkyl, —N(Rg)2, morpholino, and (C1-C6)alkoxy;
• or two Ra taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• each Rb is independently selected from the group consisting of H, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, wherein any (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, is optionally substituted with one or more groups independently selected from halo, (C3-C6)cycloalkyl, heteroaryl, and (C1-C6)alkoxy;
• or two Rb taken together with the nitrogen to which they are attached form an azetidino, pyrrolidino, piperidino, or morpholino ring;
• and
• each Rc is independently selected from the group consisting of H, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, wherein any (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, is optionally substituted with one or more groups independently selected from halo, (C3-C6)cycloalkyl, and (C1-C6)alkoxy;
• or two Rc taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• each Rd is independently selected from the group consisting of H, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, wherein any (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, is optionally substituted with one or more groups independently selected from halo, (C3-C6)cycloalkyl, and (C1-C6)alkoxy;
• or two Rd taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• Re is independently selected from the group consisting of H and (C1-C6)alkyl that is optionally substituted with one or more groups independently selected from halo, (C3-C6)cycloalkyl, —N(Rf)2, and (C1-C6)alkoxy;
• each Rf is independently selected from the group consisting of H, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, wherein any (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, is optionally substituted with one or more groups independently selected from halo, (C3-C6)cycloalkyl, and (C1-C6)alkoxy;
• or two Rf taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• and
• each Rg is independently selected from the group consisting of H, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, wherein any (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C3-C6)cycloalkyl, (C1-C6)alkanoyl, and (C1-C6)alkoxycarbonyl, is optionally substituted with one or more groups independently selected from halo, (C3-C6)cycloalkyl, and (C1-C6)alkoxy;
• or two Rg taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• wherein if HET is not substituted with one or more groups R1, then R2 is not H, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, cyclopropyl, cyclohexyl, phenyl, benzyl or 2-pyridyl.