Dithietanes. Synthesis of N-substituted 2-imino-1,3-dithietanes and 2-imino-1,3-dithietane hydrochloride

The reaction of diethylphosphoryl isothiocyanate with potassium hydrosulfide gave potassium diethoxyphosphinyldithiocarbamate ( 3a ). This salt, with methylene bromide, afforded 2-diethoxyphosphinylimino-1,3-dithietane ( 5a ) in high yield. In concentrated hydrochloric acid, 5a was hydrolyzed to 2-imino-1,3-dithietane which was isolated as a stable hydrochloride ( 7 ). The synthesis of some other N-Substituted 2-imino-1,3-dithietanes is also described.