An efficient synthesis of 4H-chromenes and 4H-pyrans derivatives via an ultrasound assisted one pot three-component reaction

Abstract

In this research, a new series of substituted 4H- pyrans and 4H-chromenes derivatives has been synthesized at ambient temperature in the presence of catalytic amount of sodium carbonate (20 mol %) via one-pot three-component cyclocondensation reactions of malononitrile, dialkylacetylenedicarboxylates and 1,3-diketones in ethanol under ultrasound irradiation. The synergistic effect of MCRs and ultrasound has been successfully demonstrated to offer an easy way for the synthesis of these compounds in excellent yields.