One-pot synthesis of annulated pyrido[2,3-d:6,5-d]dipyrimidine derivatives using nitrogen based DBU catalyst in aqueous ethanol medium

•One-pot synthesis of annulated pyrido[2,3-d:6,5-d]dipyrimidine derivatives.•DBU as an efficient catalyst for synthesis of annulated pyrimidine derivatives.•The advantages of this process are mild reaction conditions and excellent yields (72–89%).

We have reported DBU as an efficient organocatalyst for one-pot three-component synthesis of annulated pyrido[2,3-d:6,5-d]dipyrimidine derivatives using aromatic aldehyde, thio-barbituric acid and 6-amino-uracil in aqueous ethanol under reflux. The attractive advantages of this process are mild reaction conditions, environment friendly procedure, short reaction times, easy isolation of products, and excellent yields (72–89%).

Graphical abstractThis paper reported the synthesis of pyrido[2,3-d]pyrimidine derivatives via initial Knoevenagel, subsequent addition and final heterocyclization of substituted aromatic aldehydes, thio-barbituric acid and 6-aminouracil in aqueous ethanol as solvent using DBU as new organocatalyst catalyst. The results showed that a series of aromatic aldehydes were effectively used to prepare the targeted pyrido[2,3-d:6,5-d]dipyrimidine derivatives with good to excellent yields (72–89%) and there is no major effect on the yield of product by electron donating/withdrawing substituents.Figure optionsDownload full-size imageDownload as PowerPoint slide