Process for the purification of crude anthraquinone

摘要

A process has been provided for the purification of crude anthraquinone made by (1) oxidation of naphthalene to naphthoquinone (2) reaction of the oxidation product with butadiene to give tetrahydroanthraquinone and (3) oxide-hydrogenation of this reaction product with molecular oxygen to yield the crude anthraquinone, then optionally separating naphthalene, phthalic anhydride and low-boiling compounds from said crude anthraquinone. The purification of said crude anthraquinone is effected by treatment with an oxygen compound or mixture of oxygen compounds of the elements of the 1st and/or 2nd main group of the periodic system at elevated temperature, if desired in the presence of an inert solvent and the purified anthraquinone is isolated by physical separation methods from the products treated.