Organic heterocyclothiazenes. Part 18. 1,3,2-Dithiazolium salts and 1,3,2-dithiazolethiones

1,3,2-Dithiazol-1-ium chloride 6 and 5-chloro-1,3,2-dithiazol-1-ium chloride 7 have been prepared by the reaction of trimethylsilyl azide with 1-chloroethane-1,2-bis(sulfenyl chloride) and 1,2-dichloroethane-1,2-bis(sulfenyl chloride) respectively. The corresponding neutral 1-λ4δ2, 3,2-dithiazole-4-thione 8 and 5-chloro-1-λ4δ2,3,2-dithiazole-4-thione 18 were unexpectedly obtained by treatment of these salts with base. Methylation and benzylation of the thione 8 provided the 5-methylthio-1,3,2-dithiazol-1-ium 9 and 4-benzylthio-1,3,2-dithiazol-1-ium 12 salts, which on treatment with base afforded 5-methylthio-10 and 5-benzylthio-1-λ4δ2,3,2-dithiazole-4-thione 13 respectively; further alkylation provided a route to symmetrical difunctionalised cations such as 4,5-dimethylthio-1,3,2-dithiazol-1-ium iodide 11. Treatment of the dithiazolium chloride 7 with ammonia or aniline leads to 5-amino-19 and 5-anilino-1-λ4δ2,3,2-dithiazole-4-thione 20 respectively.