Zinc complexes of hydrazones and (thio)semicarbazones and their use for the treatment of cancer

A complex comprising Zn2+ and a compound a compound of formula (Ia) or (IIa):

• or an ion or poly-ion thereof, wherein:
• the ring A is a fused benzo or heteroaryl ring;
• R1 is selected from the group consisting of:
• wherein R1 is optionally substituted with one or more groups 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, (C4-C6)heterocycloalkyl, (C2-C6)alkylaminocarbonyl and (C2-C6)alkanoylamino 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(Ra)2, carboxy, (C3-C6)cycloalkyl, (C1-C6)alkoxy, (C1-C6)alkanoyl, (C1-C6)alkoxycarbonyl, (C2-C6)alkanoyloxy, (C4-C6)heterocycloalkyl, (C2-C6)alkylaminocarbonyl and (C2-C6)alkanoylamino;
• R2 is selected from the group consisting of H, phenyl, heteroaryl, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, and (C3-C6)cycloalkyl, wherein any phenyl, heteroaryl, (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(Rb)2, (C3-C6)cycloalkyl, (C1-C6)alkoxy, (C2-C6)alkanoyloxy, (C2-C6)alkoxycarbonyl, (C2-C6) alkylaminocarbonyl, and (C2-C6) alkanoylamino;
• R3 and R4 are each independently selected from H, (C1-C6)alkyl, piperidinyl, or piperazinyl, which piperidinyl or piperazinyl is optionally substituted with pyridyl;
• or R3 and each R4 taken together with the nitrogen to which they are attached form a 3, 4, 5, 6, 7, 8, or 9 membered ring that is optionally substituted with one or more groups independently selected from the group consisting of halo;
• Y is S, O, or Se;
• each Ra 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 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, and (C1-C6)alkoxy;
• or two Rb taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• Rc 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, and (C1-C6)alkoxy;
• X is S, O, —CH═CH—, or N—Raa;
• HET is selected from the group consisting of:
• wherein HET is optionally substituted with one or more groups independently selected from halo, cyano, hydroxy, nitro, —N(Raa)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(Rba)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 R2a 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(Rca)2, (C3-C6)cycloalkyl, (C1-C6)alkoxy, and (C2-C6)alkanoyloxy;
• n is 0, 1, 2, 3, or 4;
• each R3a is independently selected from halo, cyano, hydroxy, nitro, —N(Rda)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;
• Raa is 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, —N(Rga)2, morpholino, and (C1-C6)alkoxy;
• or two Raa taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• each Rba 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 Rba taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• and
• each Rca 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 Rca taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• each Rda 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 Rda taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• or a solvate thereof;
• Rea 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(Rfa)2, and (C1-C6)alkoxy;
• each Rfa 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 Rfa taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• and
• each Rga 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 Rga taken together with the nitrogen to which they are attached form a azetidino, pyrrolidino, piperidino, or morpholino ring;
• provided that for a compound of formula (Ia), when R1 is 2-pyridinyl, then R2 is not H or (C1-C6)alkyl.