Process for separating off 1-amino-4-bromoanthraquinone-2-sulphonic acid

US4246180A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Heinrich Leister
• Helmut Dittmer · Leverkusen, DE
• Hubert Schonhagen · Odenthal, DE

Key dates

• Filing date: Aug 31, 1978
• Grant date: Jan 20, 1981
• Expiry date: Aug 31, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C303/44
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for separating off 1-amino-4-bromoanthraquinone-2-sulphonic acid from the reaction mixture formed by the bromination of 1-aminoanthraquinone-2-sulphonic acid in sulphuric acid, which process comprises adjusting the sulphuric acid concentration of the reaction mixture under the prevailing conditions of temperature and pressure to effect precipitation of 1-amino-4-bromoanthraquinone-2-sulphonic acid as the sulphate and thereafter separating the resultant sulphate precipitate from the reaction mixture.