| Abstract: | In reaction with potassium butylxanthate and sodium tert-butyltrithionate, 2,5-dihydroxy-3,4,6,7-tetrachloro-2,3-dihydrobenzo[b]furan forms the products from nucleophilic substitution of a chlorine atom, i.e., O-butyl S-(2,5-dihydroxy-4,6,7-trichloro-2,3-dihydrobenzo[b]furan-3-yl) xanthate and S-tert-butyl S -(2,5-dihydroxy-4,6,7-trichloro-2,3-dihydrobenzo[b]furan-3-yl) trithiocarbonate respectively. Recyclization of the xanthate in concentrated sulfuric acid gave 4-(2,5-dihydroxy-3,4,6-trichlorophenyl)-1,3-dithiol-2-one, which was oxidized by iron trichloride to the corresponding benzoquinone. Cyclization of the trithiocarbonate in the presence of trifluoroacetic and p-toluenesulfonic acid led to 7-hydroxy-5,6,8-trichloro-3a,8b-dithiolo[4,5-b]benzo[d]furan-2-thione.Dedicated to Prof. A. Katritzky in honor of his seventieth birthday.Riga Technical University, Riga LV-1048, Latvia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1055–1060, August, 1998. |
