Equimolar quantities of aroyl isothiocyanates and aminoguanidine hydrochloride react additively in aqueous methanol affording excellent yields of 1-amidino-4-aroyl (thiosemicarbazides), isolable as hydrochlorides, picrates, or free bases. 1-Amidino-4- benzoyl (thiosemicarbazide) hydrochloride is cyclised by hydrochloric or orthophosphoric acid to 2-amino-5-benzamido-1, 3, 4-thiadiazole, by acetic anhydride to the corresponding ...
