Manufacture of dimethylaminobenzenesulfonates

US4133828A · kind A · utility

Assignee

• BASF SE

Inventors

• Horst Scheuermann · Ludwigshafen, DE
• Helmut Hoch

Key dates

• Filing date: Jul 22, 1976
• Grant date: Jan 9, 1979
• Expiry date: Jul 22, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C309/46
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Dimethylaminobenzenesulfonates are manufactured by reacting nitrobenzenesulfonates with formaldehyde and hydrogen in the presence of a hydrogenation catalyst containing a metal of atomic number from 24 to 29 and of phosphoric acid and water at a pH of from 2 to 3.5, at from 50 to 150.degree. C, under a pressure of at least 40 bars, with a residence time of from 1 to 15 minutes. The products are starting materials for the synthesis of dyes, especially of rhodamine dyes, oxazine dyes and reactive dyes, and also of pharmaceuticals and pesticides.