Introduction of Poly(4-Vinylpyridine) as an Efficient Promotor for the Synthesis of Pyrano[2,3-d]Pyrimidinones and Pyrido[2,3-d]Pyrimidines

This article describes an efficient method for the synthesis of pyrano[2,3-d]pyrimidinones and pyrido[2,3-d]pyrimidines via promotion of the condensation of aromatic aldehydes, malononitrile and barbituric acid and/or 6-amino-1,3-dimethyluracil in the presence of poly(4-vinylpyridine). All reactions are performed under mild conditions in high yields during short -reaction times. Simple procedure, use of green and nontoxic solvents, low cost, commercial availability and recyclability of the catalyst are the main advantages of this method.