A short and efficient synthesis of 5,5’ -bi-1,2,3-dithiazoles

Reaction of 1-arylethanone oximes with S 2 Cl 2 gives 4-aryl-5-chloro-1,2,3-dithiazol-1-ium chlorides, whose in situ treatment with copper powder affords 4,4’-diaryl-5,5’-bi-1,2,3-dithiazoles.