Efficient synthesis of novel pyrano[2,3-d]pyrido[1,2-a]pyrimidine derivatives via isocyanide-based three-component reactions

Abstract

The synthesis of novel tricyclic fused pyrano[2,3-d]pyrido[1,2-a]pyrimidines containing both biologically active pyridopyrimidine and pyranopyrimidine scaffolds, via the reaction of 2H-pyrido[1,2-a]pyrimidine-2,4(3H)-dione, isocyanides, and dialkylacetylenedicarboxylates are reported. The products were obtained in good to excellent yields over short reaction times and with a simple work-up procedure.