Condensation of substituted 2-aminopyridine with β-ketocarboxylic esters: 4H-pyrido[1,2-a]pyrimidin-4-ones and pyridin-2-ones
We report the condensation of substituted 2-aminopyridines 5 with β- ketocarboxylic esters in polyphosphoric acid. In this reaction were obtained together with the target compounds, 4H-pyrido[1,2-a]pyrimidin-4-ones 6 also the pyridin-2-ones 7. All the compounds 7 were tested for their calcium- antagonistic activity but failed to evoke any vasorelaxant response.