Process for the preparation of 5-fluoro-2-nitrobenzoic acid

US5756831A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Wolfram Kissener · Neunkirchen, DE
• Jurgen Kuprat · Wermelskirchen, DE
• Herbert Emde · Cologne, DE
• Klaus-Christian Paetz · Burscheid, DE

Key dates

• Filing date: Jun 20, 1996
• Grant date: May 26, 1998
• Expiry date: Jun 20, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C201/08
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

5-Fluoro-2-nitrobenzoic acid having low contents of 3-fluoro-2-nitro-benzoic acid is prepared in a simple manner by nitrating 3-fluorobenzoic acid in an anhydrous medium using an anhydrous nitrating acid and isolating and purifying 5-fluoro-2nitro-benzoic acid, by taking 7.5 to 15 parts by weight of water, based on 1 part by weight of 3-fluorobenzoic acid used, introducing the reaction mixture reacted to exhaustion into this volume of water taken, filtering off the precipitate formed and washing it with water.