Triethylamine: An efficient N-base catalyst for synthesis of annulated uracil derivativies in aqueous ethanol

The one-pot three-component reaction for the synthesis of pyrano[2,3-d]pyrimidine derivatives has been reported via initial knoevenagel,subsequent addition and final heterocyclization of substituted aromatic aldehydes,ethylcyanoacetate and barbituric acid in aqueous ethanol solvent using triethyamine as n- base catalyst under reflux condition. the results showed that a series of aromatic aldehydes were effectively used to prepare the targeted pyrano[2,3-d]pyrimidine derivatives with good to excellent yields (69-94%) and there is no major effect on the yield of product by electron donating/withdrawing substituents. environment friendly procedure,excellent yields,inexpensive and readily available catalyst are the advantages of this procedure. all synthesized compounds were characterized by ir,1hnmr and 13cnmr spectral data.