Synthesis of Benzylidene-phenylpyrrolidine-dione and Isoxazolone based Nitrogen Heterocycles and their Synthetic Transformations

Abstract

Herein, we have demonstrated a greener approach for the synthesis of isoxazole-4-(5H)ones via a one-pot cyclocondensation reaction of aromatic aldehydes, hydroxylamine hydrochloride and ethyl acetoacetate in ethanol. This method afforded isoxazole-5-(4H)-ones in high yield. 3 Arylidene pyrrolidine-2,5-diones are good Michael acceptors and show Diels-Alder reactivity across the double bond. Herein, we have demonstrated the synthesis of 3-arylidene pyrrolidine 2,5-diones via reaction of N-phenyl maleimide with triphenylphosphine and the formed TPP maleimide adduct was reacted with benzaldehyde in ethanol to give (E)-3-arylmethylidene pyrrolidene-2,5-diones in excellent yield.