ALKYL ARBONYL-1-ETHENYL)AMINO-3-DIMETHYLAMINOPROPENOATES IN THE SYNTHESIS OF FUSED PYRIMIDINONES - A FACILE ROUTE TO 3-AMINOAZINO-4H-PYRIMIDIN-4-ONE

Alkyl arbonyl-1-ethenyl)amino-3-dimethylaminopropenoates 1a,b react wi th heteroarylamines 2 to give alkyl bonyl-1-ethenyl)amino-3-heteroaryl aminopropenoates 3-13. These were cyclized into fused enzoyl-2-ethoxyc arbonyl-1-ethenyl)amino-4H-azolo-n (or azino)-pyrimidin-4-ones 14-18. 2-Benzoyl-2-ethoxycarbonyl-1-ethenyl group can be easily removed from yl)amino-8-methyl-4H-pyridol[1,2-a]pyrimidin-4-one (14) to give 3-amin o-8-methyl-4H-pyrido[1,2-a]pyrimidin-4-one (19). The structure of 1a w as confirmed by X-ray analysis.