Basf Aktiengesellschaft

Enno Spohler

Heinrich Hiller

Joerg Redeker

In a process for the manufacture of 1-amino-2-bromo-4-hydroxyanthraquinone by hydroxylating previously prepared and isolated 1-amino-2,4-dibromoanthraquinone in sulfuric acid in the presence of boric acid at from 110.degree. to 130.degree. C., the improvememt that 1-aminoanthraquinone is brominated (from 1.5 to 2.1 moles of bromine per mole) in sulfuric acid of from 50 to 85 percent strength at from 80.degree. to 130.degree. C., the reaction mixture is brought to a concentration of from 96 percent strength sulfuric acid to 5 percent strength oleum by adding oleum; and the dibromo compound is then hydroxylated in the presence of boric acid. Very pure 1-amino-2-bromo-4-hydroxyanthraquinone, which can be used for all purposes, is obtained in a high yield.

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Limburgerhof, Germany

Enno Spohler