A method for the isolation of dinitro anthraquinone with a high content of alpha, alpha ′ - dinitro compounds

摘要

A process for the isolation of mixtures of 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone which have a high content of alpha , alpha '-dinitroanthraquinones by heating a suspension of the crude dinitroanthraquinone mixture in certain organic liquids at from 60 DEG to 200 DEG C until solution equilibrium has been set up, and separating the undissolved material from the solution. The undissolved material contains more than 90% and as a rule more than 95% by weight of 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone. The pure mixture of 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone may be used for the manufacture of dyes.