One pot synthesis of bis (dihydropyrimidinone) and tetrahydro-4H-chromenes derivatives using Ag<sub>2</sub>O/GO/TiO<sub>2</sub> composite nanostructure
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