Lewis‐Säure‐ und photochemisch induzierte Dimroth‐Umlagerung von 3H,6H‐2,5‐Bis‐(p‐N,N‐dimethylaminophenyl)‐1,2‐thiazolino[5,4‐d]1,2‐thiazolin‐3,6‐dithion

Lewis-acid and Photochemically Induced Dimroth Rearrangement of 3H,6H-2,5-Bis-(p-N,N-dimethylaminophenyl) -1,2-thiazolino[5,4-d]1,2-thiazoline-3,6-dithione The reaction of 3H,6H-1,2-dithiolo[4,3-c]1,2-dithiole-3,6-dithione (5) with N,N-dimethyl-p-phenylendiamin gives, depending on the conditions of the reaction, 3H,6H-3-(p-N,N-dimethylaminophenyl-imino)-1,2-dithiolo[4,3-c]1,2-dithiole-6-thione (7), and 3H,6H-2,5-Bis-(p-N,N-dimethylaminophenyl) -1,2-thiazolino[5,4-d]1,2-thiazoline-3,6-dithione (3d). Catalyzed by Lewis acids the compound 3d rearranges reversibly into the isomeric 3H,6H-3,6-bis-(p-N,N-dimethylaminophenyl-imino) -1,2-dithiolo[4,3-c]1,2-dithiole (4d). The Dimroth type rearrangement of 3d into 4d occurs also on irradiation.