Dithiazoles and related compounds. Part 2. Synthesis of 5-aryl-1,4,2-dithiazolium salts

Abstract

Reaction of 4-methoxythiobenzoylthiohydroxylamine (2) with acyl chlorides and pyridine, or with acetic formic anhydride, gives good yields of the N-acyl derivatives (3), which may be cyclised with perchloric acid and acetic anhydride to novel 1,4,2-dithiazolium salts (4), which include the first example unsubstituted at C-3. Evidence is presented for charge delocalisation and hence aromaticity in the cations. The salts are attacked at C-5 by nucleophilic reagents, yielding 5H-1,4,2-dithiazoles.