An efficient conversion of maleimide derivatives to 2-thioxo imidazolidinones

Starting from maleimidederivatives, a series of 2-t hioxoimidazolidinones was prepared through two different procedures. These syntheses have achieved in two steps via reaction between maleimide deriva tives 1,semicarbazide hydrochloride 9 and isothiocyanates 5,the best results being obtained under acid conditi ons (AcOH or heteropolyacid in ethanol or acetonitrile) . The synthesized compounds 11a-f and substituted thiohydantoins 6a-h, 8a-h were screened for their in vitro anti-bacterial ac tivity against four bacterial strains.