Separation of 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone

US4053488A · kind A · utility

Assignee

• BASF SE

Inventors

• Hilmar Bruenemann
• Heinz Eilingsfeld · Bischofswerda, DE
• Dietrich Lach

Key dates

• Filing date: Sep 16, 1976
• Grant date: Oct 11, 1977
• Expiry date: Sep 16, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C225/34
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for separating 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone by heating a dinitroanthraquinone mixture, in a mixture of from 5 to 85 per cent by weight of N-methylpyrrolidone and from 95 to 15 per cent by weight of an organic liquid which boils at from 80.degree. to 210.degree. C and is miscible in all proportions with N-methylpyrrolidone, at from 60.degree. to 180.degree. C, and separating off the undissolved material, at the extraction temperature, after the solution equilibrium has been reached. The insoluble material contains more than 85 per cent by weight, and as a rule more than 90 per cent by weight, of 1,5-dinitroanthraquinone. From the extract, it is possible to isolate the dissolved 1,8-dinitroanthraquinone together with the dissolved 1,5-dinitroanthraquinone and any byproducts which may be present.