A convenient approach for vinylation reaction in the synthesis of 5-vinyl-2-pyrrolidinone, a key intermediate of vigabatrin

A convenient, safe and cost-effective method for carrying out the key vinylation of 5-ethoxy-2-pyrrolidinone ( 8 ) in the preparation of 5-vinyl-2-pyrrolidinone ( 2 ) in the presence of potassium carbonate is described. This present procedure is developed by replacing inherently hazardous ethyl magnesium bromide with inexpensive and eco-friendly potassium carbonate. The reaction was performed on a multi-gram scale, with vinyl magnesium bromide as the vinylation reagent, in an 81% yield to give the 5-vinyl-2-pyrrolidinone with excellent purity and without the need for chromatography.