An efficient Ni(II) laurate promoted heterocyclization of symmetrical thioureas with maleic anhydride and mechanistic approach toward higher substituted thiazolidine-4-one-5-acetic acids

Abstract

For the first time, readily available Ni(II) laurate catalyzed thia-Michael addition of symmetrical N,N-disubstituted thioureas to maleic anhydride and subsequent cyclization in toluene afforded novel thiazolidine-4-one-5-acetic acids with good yields in a short reaction time. The efficiency and low cost of the renewable, eco-friendly laurate based homogenous Lewis acid catalyst and the fact that cyclization proceeds in a much shorter time means that this synthetic method is interesting from a green chemistry point of view. The catalyst can be reused for many times without any significant loss of activity.