Process for the preparation of the lithium salt of a fiber-reactive azo dyestuff

US4939242A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Konrad Opitz · Liederbach, DE
• Marcos Segal · Suzano, BR

Key dates

• Filing date: Mar 25, 1988
• Grant date: Jul 3, 1990
• Expiry date: Mar 25, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B62/51
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of the lithium azo compound of the formula ##STR1## having an Na content of less than 0.2% by weight, in particular less than 0.1% by weight, in which the lithium salt of 4-(.beta.-sulfatoethylsulfonyl)-aniline is diazotized in an aqueous solution or in an aqueous solution containing a water-miscible organic solvent by means of nitrosylsulfuric acid, and the product is coupled with the lithium salt of 1-hydroxy-7-acetylaminonaphthalene-3-sulfonic acid.