Abstract The condensation of 2, 6-diaminopyridine and 2-acetamido-6-aminopyridine with β- keto esters in polyphosphophoric acid was studied. In this reaction some 1, 8- naphthyridinones, pyrido [1, 2-a] pyrimidinones and pyrimido [1, 2-a][1, 8] naphthyridinones variously substituted were obtained.
![7-Amino-4-methyl[1,8]naphthyridin-2-ol Structure](https://image.chemsrc.com/caspic/486/1569-15-9.png)
