: A rapid and easy solvent free one-pot synthesis of 5-arylidene-2-imino-4-thiazolidinones by condensation of the thioureas with chloroacetic acid and an aldehyde under microwave-irradiation is described. ... 4-Thiazolidinone derivatives constitute an important class of heterocyclic compounds for their potential pharmaceutical applications [1,2,3,4,5,6,7,8]. Consequently, a large number of synthetic protocols leading to these compounds have been reported in the literature [9]. ...