117-05-5Relevant articles and documents
Process for the preparation of 1-acylamino-5(8)-chloroanthraquinones
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, (2008/06/13)
The invention relates to a novel process for the preparation of 1-acylamino-5(8)-chloroanthraquinones, which are starting materials for the preparation of vat dyes. It is characterized in that 1,5(8)-dichloroanthraquinones is reacted with ammonia at temperatures of 190° to 240° C., the amino groups in the reaction mixture are completely acylated and the more sparingly soluble diacylaminoanthraquinone is separated off from the more readily soluble monoacylaminochloroanthraquinone. The new process yields reaction products which are purer and cheaper than those which are obtained by conventional methods. Moreover there are smaller waste water problems.