Nano Fe2O3, clinoptilolite and H3PW12O40 as efficient catalysts for solvent-free synthesis of 5(4H)-isoxazolone under microwave irradiation conditions

Abstract

A quick and solvent-free approach involving the exposure of neat reactants to microwave irradiation in conjunction with the use of clinoptilolite, H3PW12O40 and Fe2O3 nanoparticle catalysts is described. In this work, condensation of hydroxylamine hydrochloride, sodium acetate, acetoacetic or benzoyl acetic ethyl ester and appropriate aldehydes by employing catalysts gave 5(4H)-isoxazolone only in one step. Catalyst amount, temperature effects and catalysts reusability were monitored. Among the catalysts, Fe2O3 nanoparticles had better performance than other catalysts from viewpoint of yield and reaction time. The present protocol offers several advantages, such as short reaction time, reasonable yield, mild reaction condition and recycling catalysts with a very easy workup. © 2013 Sociedade Brasileira de Química.