Process for the preparation of 1-amino-4-bromoanthraquinone-2-sulphonic acid I

摘要

A process for preparing 1-amino-4-bromoanthraquinone-2-sulphonic acid or an alkali metal salt thereof which comprises contacting 1-amino-anthraquinone at a temperature in the range of 90 DEG to 150 DEG C. with an SO3-containing sulphuric acid (oleum) and thereafter treating the resultant sulphonated 1-amino-anthraquinone with at least 0.5 molar equivalent of bromine, relative to 1 mol of 1-amino-anthraquinone, at temperatures in the range from 60 DEG to 100 DEG C.