Transformations of anthra[1,9-cd]isoxazol-6-ones in hydrohalic acids

4-Halo-1-aminoanthraquinones are formed when anthra [1,9-cd]isoxazol-6-ones are refluxed in hydrohalic acids. The 3 position undergoes halogenation when 5-substituted isoxazoles are used. The process takes place via a one-proton mechanism with the participation of halide ion in the rate-determining step, possibly with the intermediate formation of N-haloaminoanthraquinones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1471–1473, November, 1980.