Synthesis of 2-Benzyl-3-(2-oxo-2-phenylethyl)isoindolin-1-one Derivatives in Water under Catalyst-Free Conditions

Abstract

Isoindolin-1-one derivatives, which are nitrogen-containing heterocycles, are important key intermediates for many useful organic compounds and natural products. To date, there are no syntheses for these compounds that proceed under mild reaction conditions. Therefore, in this study, we developed a catalyst-free synthesis of a series of isoindolinone derivatives involving a three-component reaction in water using o-formylbenzoic acid, benzylamine, and acetophenone as raw materials. An investigation of the influence of solvent type, substrate molar ratio, temperature, and time on the reaction revealed that the reaction proceeded optimally in water at 70 °C over 12 h. Under the optimal conditions, isoindolinone derivatives were obtained in up to 96% yield. The reaction is applicable to 20 types of substrates, and the yields were all approximately 90%. This method has the advantages of mild reaction conditions, environmental friendliness, and a broad substrate scope.