Sonochemical synthesis of l,4-dihydropyrimidinones catalyzed by reduced graphene oxide encapsulated zinc oxide nanoparticles

A simple and efficient one-pot procedure for the synthesis of 1,4-dihydropyrimidinones in ethanol under ultrasound irradiation is described. These heterocyclic compounds were prepared through condensation of aromatic aldehyde, ethyl acetoacetate, urea, or thiourea in the presence of ZnO NPs@rGO nanocomposite as a convenient and reactive catalyst. This protocol has very advantages such as low loading catalyst, excellent product yields, and short reaction times. The structures and morphology properties of ZnO NPs@rGO nanocomposite was investigated by FTIR, XRD, FE-SEM. and EDX techniques. Furthermore, the organic products were identified by melting points, FTIR, and H-1 NMR analyses.