Production of virtually pure 1-amino-8-nitro-4,5-dihydroxyanthraquinone

US4154747A · kind A · utility

Assignee

• BASF SE

Inventors

• Gerhard Epple · Bad Dürkheim, DE
• Wolfgang Elser · Fairfax, US
• Walter Himmele · Monsheim, DE

Key dates

• Filing date: Jun 20, 1978
• Grant date: May 15, 1979
• Expiry date: Jun 20, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2603/24
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of 1-amino-8-nitro-4,5-dihydroxyanthraquinone by partially reducing the corresponding dinitrohydroxyanthraquinone and isolating the reduction product, in which crude 1,8-dinitro-4,5-dihydroxyanthraquinone obtained by nitrating 4,5-dihydroxyanthraquinone is partially reduced in a phenol-water mixture, which contains from 5 to 50% by weight of water, in the presence of an alkali metal phenolate, by means of a reductone, reductonate or a mixture of these. The product is virtually free from by-products and is suitable for use for the synthesis of dyes.