(1,2-5,6)-ANTHRADIQUINONES BY OXIDATION OF 2,6-DIHYDROXYANTHRACENES

For the synthesis of the ortho-anthraquinones 4-6 and 15 from the corr esponding 2,6-dihydroxyanthracenes 1-3 and the 2-hydroxyanthracene 14, respectively, we performed a comparative study of the known reagents used for o-quinone preparation from phenols, namely phenylseleninic an hydride, potassium nitrosodisulfonate and tert-butyl hydroperoxide wit h the Mimoun complex as catalyst. Only phenylseleninic anhydride gave the expected compounds in satisfying yields.