Diammonium hydrogen phosphate as a versatile and efficient catalyst for the one-pot synthesis of pyrano[2,3-d]pyrimidinone derivatives in aqueous media.

Diammonium hydrogen phosphate, (NH4)2HPO4, was used as a catalyst for one-pot, three-component condensation reactions consisting of aromatic aldehydes, malononitrile and barbituric/thiobarbituric acid in aqueous ethanol at room temperature. This method has the advantages of a simple operation, mild reaction conditions, high yields, by using a less toxic and low cost chemical as a catalyst.