Chemistry of Iminothiazolidinone Heterocycles

Thioureas are exceptionally versatile building blocks towards the synthesis of wide variety of heterocyclic systems, which also possess extensive range of bioactivities. Thiourea derivatives serve as precursors for the synthesis of five membered heterocycles with imino moiety like methyl 2-[2-benzamido-3-(2-benzothiazolyl)-4-oxothiazolidin-5-ylidene]acetates and ethyl 4-[2-benzamido-5-(2-methoxy-2-oxoethylidene)-4-oxothiazolidin-3-yl]benzoates. They were prepared in good yields, by the direct cyclization of these thioureas with dimethyl but-2-ynedioate (DMAD) in methanol. Iminothiazolidinones and their derivatives exhibit a wide variety of chemotherapeutic activities.