The reactions of the title compounds are governed by sulfur redox chemistry. Thus, cyanothioformamide 2 reacts with aryl isocyanates 3a−c to give bis[3-aryl-1-(arylcarbamoyl)-2-oxo-4-(arylcarbamoylimino)imidazolidin-5-yl] disulfides 6, as shown by an X-ray crystallographic investigation of product 6a. Reaction with methylisocyanate (3d) gives the related trisulfide 7d along with disulfide 6d. A desulfurized