Combustion Derived Nanocrystalline-ZrO₂ and Its Catalytic Activity for Biginelli Condensation under Microwave Irradiation

摘要

Nanocrystalline zirconium(IV) oxide (nc-ZrO₂) possessing high surface area was synthesized by a low temperature eco-friendly solution combustion method using a new organic fuel alanine. The powder XRD, SEM and surface area measurements were carried out for characterization of nc-ZrO₂. The powder XRD results revealed that, the nc-ZrO₂ has the pure tetragonal phase. The crystallite size calculated by Scherrer's formula and BET surface area were found to be ca. 53–57 nm and ca. 275 m2/g, respectively. SEM micrograph exhibited the macroporous nature of the powder. nc-ZrO₂ has been employed as a catalyst for the solvent-free synthesis of 3,4-dihydro- pyrimidin-2-ones (DHPMs) by a microwave (MW) assisted one-pot, multicomponent Biginelli condensation reaction of araldehydes, ethylacetoacetate and urea or thiourea. DHPMs are obtained in good to excellent yields (85%–96%) under this reaction condition within short interval of time (10–20 min).