6-Chloro-3H-benzo[d][1,2,3]dithiazol-2-ium Chloride

This short note describes the synthesis of an amorphous benzo[1,2,3]dithiazole chloride salt (commonly known as a ‘Herz salt’) by use of the Herz reaction. Hetero- and homolytic transformations of this species to a variety of useful adducts in medicinal and materials chemistry are well established, although there are limited examples of isolation in the literature, and characterisation data is even harder find. While several studies have confirmed the structure of the benzodithiazole ring beyond doubt, (having generated suitably crystalline salts with large counterions for XRD-analysis), there remains value in understanding and optimising the synthesis of the simple, amorphous polymorphs. For the first time, MS data is provided for this compound and a new mechanism of its formation is proposed based upon new experimental observations and data.