SYNTHESIS OF 2,4-DIAMINO-5-ACETYL(ETHOXYCARBONYL)PYRIMIDINES FROM BETA-DICARBONYL COMPOUNDS AND DICYANDIAMIDE AND THEIR USE FOR BUILDING A PYRIMIDO (4,5-D) PYRIMIDINE SYSTEM

2,4-Diamino-5-acetyl(ethoxycarbonyl)-6-methyl(phenyl)pyrimidines were obtained by the reaction of acetylacetone and beta-ketocarboxylic acid esters with dicyandiamide in the presence of Ni(OAc)2. It was shown that annelation of the pyrimidine ring with this compound provides a convenient method for building the pyrimido[4,5-d]-pyrimidine system. New derivatives of 2-aminopyrimido[4,5-d]pyrimidine, 7-amino-3H-pyrimido[4,5-d]-pyrimidin-4-one, and 7-amino-1H,3H-pyrimido[4,5-d]-pyrimidine-2,4-dione were synthesized.