PREPARATION OF 1,4,2-DITHIAZOLIUM SALTS

N-(Substituted formyl)dialkylamino(thioxo)-methanesulfenamides (R2NCSSNHCOR' 3: R = alkyl, R' = alkyl, dialkylamino, alkoxy, and heterocyclic substituent) were treated with a strong acid (HBF4 or HClO4) in Ac2O to afford 1,4,2-dithiazolium salts (7) and/or 3,5-bis(dialkyliminio)-1,2,4-trithiolanes (9). The reactivity is markedly dependent on the nature of substituents (NR2 and R') and the acid used. For R' = MeO, the sulfenamides reacted successively with NaH and p-toluenesulfonyl chloride to give methyl bis(dialkylthiocarbamoylthio)carbamates (10). The mechanisms for the formation of 9 and 10 are discussed.