A catalytic three-component synthesis of isoxazol-5(4H)-ones under green conditions

Abstract

The three-component cyclocondensation of various aryl/heteroaryl aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/ethyl 4-chloro-3-oxobutanoate have been established for the synthesis of isoxazol-5(4H)-ones using sodium malonate as an efficient catalyst. This reaction has been performed in water as a green reaction medium at 25°C. Optimization of the reaction conditions show that the reaction performs better in aqueous medium, at room temperature, and in the presence of 10 mol% of the catalyst. This procedure has several unique features, including shorter reaction times, easy separation of pure products, avoiding the hazardous organic solvents, simplicity of experimental procedures, operationally simple, and eco-friendly.