Nucleophilic addition to the phenoxazonium cation

At the instant of its formation of oxidation of phenoxazine with ferric chloride, the phenoxazonium cation adds arenesulfinate and nitrite ions to give 3-arylsulfonyl- and 3-nitrophenoxazines, respectively. It is shown that the introduction of a second sulfonyl group proceeds more slowly and gives 3,7-di(arylsulfonyl)phenoxazines in low yields. The PMR spectra of the synthesized compounds are examined in comparison with 3-substituted phenothiazines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 616–618, May, 1977.