Process for the preparation of a mixture of 1-amino-2-chloro-4-hydroxyanthraquinone and 1-amino-2-bromo-4-hydroxyanthraquinone

US4767573A · kind A · utility

Assignee

• Ciba-Geigy · US

Inventors

• Rolf Muller · Karben, DE
• Bernd Dill · Rheinfelden (Baden), DE

Key dates

• Filing date: Jun 10, 1987
• Grant date: Aug 30, 1988
• Expiry date: Jun 10, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B1/503
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of a mixture of 1-amino-2-chloro-4-hydroxyanthraquinone and 1-amino-2-bromo-4-hydroxyanthraquinone, which mixture contains a high proportion of 1-amino-2-chloro-4-hydroxyanthraquinone, by chlorinating and brominating 1-aminoanthraquinone and reacting the intermediate so obtained with concentrated or fuming sulfuric acid.