A Versatile Synthesis of 2-Amino-4H-pyrido[1,2-a][1,3,5]triazin-4-ones from 2-Aminopyridines.

The quasi-one pot synthesis of new 2-aminopyrido[1,2-a][1,3,5]triazin-4-ones starting from 2-amino-pyridine and 2-aminopicolines is herein described in order to obtain a library of cyclic guanidines.