PURPOSE: To prepare highly pure 1,5- and 1,8-diphenoxyanthraquinones useful as intermediates for production of dyes, separately, in high yield, by separating the mixture of 1,5- and 1,8-diphenoxyanthraquinones into the individual constituents, taking advantage of the difference of the solubilities and using a small amount of an inexpensive solvent in place of mercury.
CONSTITUTION: An alcohol is added to the mixture of 1,5- and 1,8-diphenoxyanthraquinones obtained by the conventional phenoxylation. The alcohol is, e.g. methyl alcohol, ethyl alcohol, etc. The alcohol is slowly dropped into the mixture near the boiling point. The solution is cooled and filtered to give 1,5-diphenoxyanthraquinone having low solubility. 1,8-Diphenoxyanthraquinone having high solubility is deposited by cooling the filtrate or diluting it with an alchol and cooling the solution.
AIGA HIROSHI
KAMICHI NOBUO
