Syntheses with Halogen Derivatives of Thiophene and Benzothiophene

Article abstract of DOI:10.1021/jo01299a023

Pyrolysis of octachlorotetrahydrothiophene 1,1-dioxide provides a practical synthesis of octachlorocyclobutane. 1,2-Dichlorohexafluorotetrahydrothiophene 1,1-dioxide also yields a cyclobutane.Treatment of these sulfones with potassium hydroxide forms perhalogenated 3-butenesulfonates.From octachloro-2,3-dihydrobenzothiophene 1,1-dioxide, octachlorostyrene is produced by pyrolysis and hexachlorobenzothiophene 1,1-dioxide by treatment with sodium iodide.Hexachlorobenzothiophene has been prepared from octachloro-2,3-dihydrobenzothiophene and oxidized with chromium trioxide to a thiolactone (17).Hydrolysis of the latter gives a 2H-benzothiete (18).Oxidation of tetrachlorothiophene forms the thiolactone tetrachloro-2,3-dihydrothiophen-2-one (19).Octachlorodibenzothiophene can be made by direct chlorination.