A simple and efficient synthesis of some novel thiazolidine-4-one derivatives

Reaction of 4‐phenylthiosemicarbazide with dialkyl acetylenedicarboxylate in CH2Cl2 at 0°C lead to construction of alkyl 3‐amino‐2‐phenyliminothiazolidine‐4‐one‐5‐ylidene acetate in a few minutes and good yields. Alternatively, the use of thiosemicarbazide has given the corresponding 3‐amino‐2‐iminothiazolidine‐4‐one‐5‐ylidene acetate, while application of di‐t‐butylacetylenedicarboxylate in these reactions has not entailed with cyclization. J. Heterocyclic Chem., (2010).