Expeditious synthesis of (±)-diethyl 2-alkyl- and 2-aryl-(3-oxoisoindolin-1-yl)phosphonates catalysed by OSU-6

Abstract

A one-step strategy to prepare (±)-diethyl 2-alkyl- and 2-aryl-(3-oxoisoindolin-1-yl)phosphonates is reported via a modified Kabachnik–Fields condensation of 2-carboxybenzaldehyde with an amine and triethyl phosphite using OSU-6, an MCM-41 type mesoporous hexagonal silica, as the catalyst. The reaction proceeds to form the target compounds in high yields with minimal purification requirements. The method is successful for benzylic, aromatic and aliphatic amines. An additional advantage of the current method is that the catalyst can be recycled up to four times with useful activity.