Derivatives of thiazolidinone ring systems are known to act as anti-HIV infections , analgesic, anti-bacterial, anti-convulsant, anti parasitic, potential anti-inflammatory and herbicidal agents. Due biological activities of thiazolidinones ring, several methods for their synthesis have been illustrated in literature. Imidazolidine-2-thiones were synthesized by the oxidative cyclization of 1-benzoyl-3-aryl-thioureas with bromine and enolizable carbonyl compounds in the presence of excess triethylamine . A suitable method for the synthesis of fused thiazoles were described from the reaction of aroylphenyl thioureas with π-acceptor quinones. An efficient and one-pot method for the synthesis alkyl 2-(1-alkyl-5-oxo-3-phenyl-2-thioxotetrahydro-4H-imidazol-4-yliden) acetate derivatives via simple reaction between isoquinoline, dialkyl acetylenedicarboxylate and benzyl phenylthiourea under solvent-free conditions without using any additional catalyst, is described. The mild reaction conditions and good yields and exhibit the synthetic advantage of this method. Also this method is environmentally friendly.