Facile, eco-friendly and one-pot synthesis of 3,4-disubstituted isoxazol- 5(4<em>H</em>)-ones using starch solution as a reaction media

Abstract

A one-pot three-component reaction of ethyl acetoacetate with hydroxylamine hydrochloride and various aromatic aldehydes has been developed using starch solution as a reaction media. Starch solution has been employed as an environmentally benign and commercially available catalytic system for this synthesis. This cyclo-condensation reaction has been performed in aqueous ethanol as an environmentally benign solvent at 90°C as well as under microwave irradiation (MWI, 300 W) giving 3,4-disubstituted isoxazol-5(4<em>H</em>)-one derivatives in excellent yields. The use of a nontoxic, reusable and biodegradable catalytic system is one of the superior advantages of this protocol. The superior features of the present methodology are mild reaction conditions, excellent yields, high atom-economy, easy work-up process, short reaction times and use of microwave irradiation conditions.