Process for the preparation of N,N'-disubstituted 1,4-diaminoanthraquinones

US5639896A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Dietmar Kalz · Neunkirchen, DE
• Reinold Schmitz · Blecher, DE
• Karl-Heinz Reinhardt · Leverkusen, DE
• Josef Schroder · Leverkusen, DE
• Stephan Michaelis · Leverkusen, DE

Key dates

• Filing date: May 3, 1996
• Grant date: Jun 17, 1997
• Expiry date: May 3, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B1/262
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of N,N'-disubstituted 1,4-diaminoanthraquinones has been found which is characterized in that 1,4-dihydroxyanthraquinones are reacted with aliphatic or aromatic amines in the presence of a hydroxycarboxylic acid as a condensation auxiliary.