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

Abstract

Nanocrystalline zirconium(IV) oxide (nc-ZrO 2 ) 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-ZrO 2 . The powder XRD results revealed that, the nc-ZrO 2 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 m 2 /g, respectively. SEM micrograph exhibited the macroporous nature of the powder. nc-ZrO 2 has been employed as a catalyst for the solvent-free synthesis of 3,4-dihydropyrimidin-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).

Application of Nanocatalysts in Multi-Component Reactions

“…This catalyst also, recycled and reused for five cycles without any appreciable change in its activity (Scheme 58). 85 In addition, synthesis of pyrido[2,3-d]pyrimidine derivatives over ZrO 2 nanopatricles was examined by Abdolmohammadi et al 86 They tried to use this procedure for different types of aldehydes but the yields of the products of aliphatic form were low. It was observed that the best results were obtained in the absence of solvent and the yield was not increased as the reaction temperature was raised (Scheme 59).…”

Combustion-derived CuO nanoparticles: An effective and environmentally benign catalyst in the synthesis of aromatic nitriles from aromatic aldehydes

“…Simple experimental procedures, high yields, improved selectivity, and cleaner reactions of many microwave-induced organic transformations offer additional advantages. Our ongoing research program is aimed at developing environmentally benign synthetic methodologies suitable for organic compounds that are widely used [55,56]. We were therefore inspired to attempt the microwave-assisted synthesis of aromatic nitriles from aromatic aldehydes under solvent-free conditions using catalytic amounts of copper oxide NPs.…”

Boron Trioxide–Alumina as a Heterogeneous Catalyst in a Facile Solvent Free One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones

“…Consequently, many improved methods have been reported for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones in the presence of various catalysts. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Although the reported methodologies are suitable for certain syntheses, some of these procedures suffer from disadvantages, such as a long reaction time, low yield, the use of volatile organic solvents, requirement of excess reagents or costly catalysts and harsh reaction conditions. Owing to the importance of 3,4dihydropyrimidin-2(1H)-ones from the pharmaceutical, industrial and synthetic points of view, introduction of an efficient method for the preparation of these compounds is still in demand.…”