in Wiley Online Library (wileyonlinelibrary.com).Reaction of 4-phenylthiosemicarbazide with dialkyl acetylenedicarboxylate in CH 2 Cl 2 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.