Continuous manufacture of anthranilic acid

US4233459A · kind A · utility

Assignee

• BASF SE

Inventors

• Gerhard Kilpper · Battenberg, DE
• Johannes Grimmer · Aarhus, DK

Key dates

• Filing date: Mar 28, 1979
• Grant date: Nov 11, 1980
• Expiry date: Mar 28, 1999

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C227/22
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Anthranilic acid is manufactured continuously by reacting an alkali metal phthalamate and/or phthalimidate with an alkali metal hypohalite in a reaction tube, the resulting anthranilic acid being treated, during or after the reaction, with reducing agents in two steps, the reducing agents employed in the two steps being different from one another, and an alkali metal dithionite or alkali metal formaldehyde-sulfoxylate being used as the reducing agent in the second treatment step. The product is a starting material for the preparation of dyes, crop protection agents and scents.