Methyl 2-[bis(acetyl)ethenyl]aminopropenoate in the synthesis of heterocyclic systems

Methyl 2-bis(acetyl)ethenyl]aminopropenoate ( 4 ) was prepared in 3 steps from acetylacetone ( 1 ) via 4-(N,N-dimethylamino)-3-acetylbut-3-en-2-one ( 2 ) and methyl N-2,2-bis(acetyl)ethenyl]glycinate ( 3 ). Compound 4 reacts with N- and C-nucleophiles to give fused heterocyclic systems. Derivatives of pyrido1,2-a]pyrimidones 14–16 and thiazolo3,2-a]pyrimidones 17 and 18 were prepared from 2-aminopyridines and 2-aminothiazoles, respectively. With C-nucleophiles derivatives of pyrido1,2-a]-pyridinone 19 and 2H-1-benzopyran-2-one 20–22 were prepared.