PHOTO-NUCLEOPHILIC SUBSTITUTION REACTION OF HALOGENOANTHRAQUINONE IN CONCENTRATED SULFURIC ACID PHOTO-HYDROXYDEHALOGENATION
The photo-reaction of halogen-substituted anthraquinones in sulfuric acid was studied with near UV or visible light. α-Chloro-substituted anthraquinones were photo-hydroxylated mainly to form α-hydroxyanthraquinones in fairly good yields. However, β-halogenoanthraquinones gave no dehalogenated products under the same conditions.