Practical synthesis of 4H-pyrido[1, 2-a]pyrimidin-4-ones using ethylene glycol as a promoting solvent

Abstract

A simple and useful protocol leading to different 4H-pyrido[1, 2-a] pyrimidin-4-ones have been established by cyclization of various 2-amino pyridines with β-oxo ester or alkynoate. The use of ethylene glycol was demonstrated to facilitate this condensation. This reaction proceeds by nontoxic, cheap, environment friendliness and biodegradable solvent at the normal green atmospheric condition in the absence of catalyst.