Process for preparing 3-fluoro-4,6-dichlorotoluene

US5684217A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Franz-Josef Mais · Düsseldorf, DE
• Werner Bussmann · Leverkusen, DE
• Helmut Fiege · Leverkusen, DE

Key dates

• Filing date: Dec 13, 1995
• Grant date: Nov 4, 1997
• Expiry date: Dec 13, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C17/12
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

3-Fluoro-4,6-dichlorotoluene can be prepared in a particularly favourable manner by first chlorinating 3-fluorotoluene at low temperature in the presence of a Friedel-Crafts catalyst and a heterocyclic cocatalyst to give a mixture containing 3-fluoro-4-chlorobenzene and 3-fluoro-6-chlorobenzene, and subsequently, without intermediate isolation, further chlorinating this mixture, at higher temperature, after addition of further Friedel-Crafts catalyst and further heterocyclic cocatalyst, to give 3-fluoro-4,6-dichlorotoluene.