Synthesis of pyrido[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-7(8<Emphasis Type="Italic">H</Emphasis>)-one derivatives from 5-acetyl-4-aminopyrimidines and β-dicarbonyl compounds

Heating of 5-acetyl-4-aminopyrimidine derivatives with ethyl acetoacetate, ethyl benzoylacetate, and diethyl acetone-1, 3-dicarboxylate in the absence of a base gave the corresponding 6-acylpyrido2, 3-d]pyrimidin-7(8H)-ones. Under analogous conditions, the reaction with ethyl malonate afforded ethyl 7-oxo-7, 8-dihydropyrido2, 3-d]pyrimidine-6-carboxylates. The pyridone (rather than hydroxypyridine) structures of the pyridopyrimidines obtained were confirmed by IR spectroscopy.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 770–773, March, 2005.