Oxidation and reduction of some methoxy-anthracenes and their derivatives

Abstract

Solutions of 2,6,9-trimethoxyanthracene undergo rapid and quantitative photo-oxidation to 2,6-dimethoxy-9,10-anthraquinone in normal laboratory daylight. Reduction of this quinone with cyclohexyl toluene-p-sulphonate in the presence of zinc gives a mixture of the corresponding anthracene and 2,2′,6,6′-tetramethoxy-9,9′-bianthryl. Aerial oxidation of 2,6-dimethoxyanthrone in basic media results in formation of the anthraquinone together with the 9,9′-dianthraquinone (V) and other further cyclised quinones (VI) and (VII). These reactions are accompanied by novel oxidative demethylation giving 2-hydroxy-6-methoxyanthraquinone.