Process for the preparation of N-acetylaminoarylsulfonic acids in sulfuric acid as solvent

US4487725A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Otto Arndt · Hofheim, DE
• Theodor Papenfuhs · Frankfurt, DE

Key dates

• Filing date: May 17, 1983
• Grant date: Dec 11, 1984
• Expiry date: May 17, 2003

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C303/22
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to salt-free N-acetylaminoarylsulfonic acids, their preparation by acetylation with acetic anhydride or acetyl chloride, sulfuric acid, which can also contain a small amount of water and/or dimethylformamide and/or N-methylpyrrolidone, serving as the solvent, and the use of the N-acetylaminoarylsulfonic acids for the preparation of their acid chlorides.