Preparation of azo dyestuffs by diazotization and coupling in the presence of an ester

US4795807A · kind A · utility

Assignee

• Cassella Aktiengesellschaft · DE

Inventors

• Ulrich Buhler · Alzenau, DE
• Friedrich Schophoff · Frankfurt am Main, DE
• Wolf Weidemuller · Frankfurt am Main, DE

Key dates

• Filing date: Mar 30, 1987
• Grant date: Jan 3, 1989
• Expiry date: Mar 30, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B67/0029
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Azo disperse dyestuffs are prepared by diazotization and coupling in an aqueous phase, the coupling being carried out in the presence of an ester of a lower aliphatic carboxylic acid.