One pot synthesis of bis (dihydropyrimidinone) and tetrahydro-4H-chromenes derivatives using Ag2O/GO/TiO2 composite nanostructure

Abstract

In this study, a simple and efficient synthesis reaction was used to prepare Bis (dihydropyrimidinone) derivatives through Biginelli condensation reaction of terephthalic aldehyde, 1,3-dicarbonyl compounds and (thio) urea or guanidine and tetrahydro-4H-chromenes via one pot condensation of aromatic aldehydes, malononitrile, and dimedone with Ag2O/GO/TiO2 composite nanostructures as the catalyst. The structural functionalities and morphological observations of catalyst were obtained using characterization techniques of field emission scanning electron microscopy, X-ray diffraction, Fourier transfer infrared (FT-IR) spectroscopy and transmission electron microscope. The structures of Bis (dihydropyrimidinone) and tetrahydro-4H-chromenes were confirmed by FT-IR, NMR, and mass spectroscopy. Excellent yields of products, simple reaction process and simple work-up are attractive features of these effective synthesis methods.