Alkylthiosubstituted Bis(benzene-1,2-dithiolato)zincates, Benzene-1,2-dithioles, and -1,2-dithiolates - Educts for Dibenzo(1,2,5,6)tetrathiocins, and Benzo(1,2,3)trithioles; Investigations on Benzodithietes and ortho-Dithiobenzochinones

Article abstract of DOI:10.1002/prac.19943360512

Using benzenehexathiolate 1 it is possible to synthesize alkylthio-substituted benzo-1,3-dithiole-2-thiones 2, or -ones 3 and benzo-di(1,3-dithiole-2-thiones) 4, or- ones 5, resp., which were cleaved under basic conditions.The generated benzene-1,2-dithiolates 7 were isolated as benzene-dithiolato zincates 8, benzene-1,2-dithioles 11, and benzene-1-thiole-2-thiolates 10.Dibenzo(1,2,5,6)-tetrathiocins 9 were synthesized by oxidation of 7 or 8 in good yields.For the per(methylthio)-substituted tetrathiocin 9a the twist conformation was proved by x-ray structure analysis.The tetrathiocin 9a was probably formed via the orthodithiobenzoquinone 13a.Photolysis of 3a at room temperature in solution led to 9a and tetrakis(methylthio)benzo(1,2,3)trithiole 12a as the main product, which was also formed by irradiation of 9a.The trithioles 12 were formed from 8 by reaction with sulfur dichloride. 12a was investigated byx-ray structure analysis. ortho-Dithiobenzoquinone 13c can be claimed as an intermediate upon irradiation of benzo-1,3-dithiol-2-one 3c in an argon matrix at 10 K.Depending on the wavelength the equilibrium lies either on the side of dithiobenzoquinone 13c or benzodithiete 14c.The same is true for system 15/16 which can be reached by flash vacuum pyrolysis of 3c.