Reactions of alkyl (Z)-2-[(E)-2-cyano-2-(2-pyridinyl)ethenyl]amino-3-dimethylaminopropenoates with C- and N-nucleophiles. The synthesis of fused 2H,5H-pyran-2,5-diones, 4H-pyrimidin-4-ones, and 1-heteroaryl-1H-imidazole-4-carboxylates

Alkyl (Z)-2- E(E)-2-cyano-2-(2-pyridinyl)ethenyl] amino-3-dimethylaminoprop enoates (2) and (3) were transformed with C-and N-nucleophiles into alkyl 2 -[2-cyano-2-(2-pyridinyl)ethenyl]amino-3-,SH-benzo-[b]pyran-2,5-diones (14) and (15), 2H,SH-pyrano[4,3-b]pyran-2,5dione (16), 2H, SH-pyranoE3,2-c]benz o[blpyran-2,5-dione (17), alkyl 2-C2-cyano2-(2-pyridinyl)ethenyl] amino-3 - arylamino- (28-40), and 3 -heteroarylaminop rop enoates (41-43), pyrido[l,2 -a]pyrimidin-4-ones (50-53), thiazolo[3,2-a]pyrimidin4-one (54), benzothiaz oloE3,2-a]pyrimidin-4-one (55), and I-heteroaryl- 1H-imidazole-4-carboxylat e (56). Compounds (28-43) exist in (2E, 2'E) form or as a mixture of(2E, 2' E) as a major and (2Z,2'E) form as a minor isomer.