Continuous preparation of anthranilic acid

US4276433A · kind A · utility

Assignee

• BASF SE

Inventors

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

Key dates

• Filing date: Jan 10, 1979
• Grant date: Jun 30, 1981
• Expiry date: Jan 10, 1999

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C227/04
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the continuous preparation of anthranilic acid by a two-stage reaction of an alkali metal phthalamate and/or an alkali metal phthalimidate with an alkali metal hypohalite, the first stage being carried out substantially adiabatically and both stages being carried out at high flow rates and different temperatures, wherein first the phthalimide and/or phthalamic acid is dissolved in a defined excess amount of alkali metal hydroxide solution and the solution is only then mixed, and reacted, with the hypohalite, without further addition of excess alkali. The products are starting materials for the preparation of dyes and scents.