(thio, oxo, and seleno) semicarbazone derivatives and their use for treating cancer

A compound selected from compounds of formulas (I) or (II):

• and salts thereof, wherein:
• 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;
• provided that if R1 is 2-pyridinyl, then R2 is not H or (C1-C6)alkyl;
• Y is S, O, Se;
• 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;
• 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;
• and
• each 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.