An easy approach for the synthesis of N-substituted isoindolin-1-ones

A practical and efficient two-step synthesis of N-substituted isoindolin-1-ones was developed. The one-pot reaction of 2-formylbenzoic acid with amines and dimethyl phosphite proceeds in short time either with conventional heating or microwave irradiation under catalyst-free conditions to afford the corresponding N-substituted dimethyl 3-oxoisoindolin-1-ylphosphonates in good yield which, by means of a dephosphonylation reaction with lithium aluminum hydride, give the target N-substituted isoindolin-1-ones in moderate to good yield.