Ethyl 2-amino-4-aryl-1, 4-dihydro-6-phenylpyrimidine-5-carboxylates readily react, under
microwave irradiation and solvent-free conditions, with 3-formylchromone or diethyl
(ethoxymethylene) malonate to yield novel pyrimido [1, 2-a] pyrimidines. The structure of the
final products, deduced from the spectral data and confirmed by X-ray analysis, allows us to
suggest reaction pathways.