Abstract:

Nine 7-amino-6-cyano-5-aryl-5H-pyrano[2,3-d] pyrimidine-2,4(1H,3H)-diones were synthesized via the onepot threecomponent condensation reactions of aromatic aldehydes, malononitrile and barbituric acid in aqueous media without catalyst under the irradiation of microwave. The reactants were mixed in an equal molar ratio, and exposed to MW irradiation for 5~15 min, and the yields were 80%~92%. This method avoided the long reaction time of usual synthesis route and the troubles of isolation the intermediate and minimized the environmental pollution. The structures of the products were characterized by IR, ¹H NMR spectroscopies and elemental analysis.

Key words: Pyrano[2,3-d]pyrimidine, microwave irradiation, one-potsynthesis, aqueous media