A highly efficient one-pot multicomponent synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones catalyzed by strontium pyroarsenate nano-plates

摘要

The present work describes the one-pot multicomponent synthesis of heterocyclic 3,4-dihydropyrimidin-2-(1H)-ones and thiones (DHPMs) under solvent-free conditions by Sr2As2O7 nanocatalyst. Sr2As2O7 nanocatalyst was synthesized by solvothermal reactions at stoichiometric molar ratio. The characterizations of the as-prepared nanomaterials were performed by X-ray powder diffraction (XRPD) and fourier-transform infrared (FTIR) techniques. According to Rietveld analysis data, it was found that reaction time had a considerable effect on crystal phase change from monoclinic to tetragonal crystal system. Field emission scanning electron microscope (FESEM) images showed that the morphology of the obtained materials was changed by increasing the reaction time, from 24 to 120 h, from long-length rods to multigonal plates. Catalytic activity of the nanomaterials was investigated in Biginelli reactions for the synthesis of heterocyclic DHPMs compounds. The synthesis yields at optimum conditions were 94% and 96% for S-1 and S-5, respectively. Langmuir-Hinshelwood kinetic model revealed that the reactions followed a pseudo-first order kinetic model. (c) 2020 Published by Elsevier B.V.