The syntheses of 1,2‐benzodithiino[5,4,3‐cde][1,2]benzodithiin‐2,7‐diamine (1) and dithio‐bridged benzidine 2 have been achieved. The starting material for the synthesis of 1 was 1,3‐diiodo‐5‐nitrobenzene (15) which was transformed by conventional means into 1,2‐bis[3,5‐bis(ethylthio)phenyl]diazane (19). The benzidine rearrangement of 19 in the presence of HBF4 at –30 °C yielded 4,4′‐diamino‐2,2′,6,6′‐tetraethylthiobiphenyl (20) in 50 % yield. Treatment of 20 with sodium in ammonia and work‐up in the presence of air yielded 1. The latter compound could be reduced with LiAlH4 to the tetrathiol 20a. The starting material for the preparation of 2 was 3‐chloro‐1‐iodo‐5‐nitrobenzene (23), a side product of the preparation of 15. It was transformed analogously to the preparation of 1 into 1,2‐bis(3‐ethylthiophenyl)diazane (28). The benzidine rearrangement of 28 in presence of HBF4 at –30 °C afforded 4,4′‐diamino‐2,2′‐bis(ethylthio)biphenyl (29) in 49 % yield. Treatment of 29 with sodium in ammonia and work‐up under aerobic conditions yielded 2. Quantitative reduction of 2 to the thiol 29a could be achieved with LiAlH4. The reversible electrochemical reduction of 1 on unmodified glassy carbon electrodes leads to a product to which the structure of 3 was assigned.

Syntheses and Properties of S 2 -Bridged Benzidines. -The synthesis of the title compounds (VII) and (XII) is achieved via benzidine rearrangement of the diazanes (IV) and (IX). Their physical and electrochemical properties are studied. -(ZHU-OHLBACH, Q.; GLEITER, R.; ROMINGER, F.; SCHMIDT, H.-L.; REDA, T.; Eur.