Nucleophilic substitution of hydrogen (9-H) in acridinium salts by phenols

Under oxidative conditions, quaternary and protic acridinium salts undergo substitution of the hydrogen atom in the 9 position by a phenol residue to give 9-hydroxyarylacridines. The latter may be formed under the same conditions from complexes of acridine hydrochloride with phenols obtained by an independent method.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 266–271, February, 1976.