Process for the preparation of substituted 2,3-difluoropyridines

US5468863A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Ralf Pfirmann · Griesheim, DE
• Theodor Papenfuhs · Frankfurt, DE

Key dates

• Filing date: Feb 18, 1993
• Grant date: Nov 21, 1995
• Expiry date: Feb 18, 2013

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D213/61
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a novel process for the preparation of substituted 2,3-difluoropyridines by reaction of substituted 2,3-halopyridines with fluoride salts in the presence of phase transfer catalysts, preferably in polar aprotic solvents, without removing the resulting substituted 2,3-difluoropyridines continuously from the reaction mixture. The substituted 2,3-difluoropyridines which can be prepared according to the invention are, inter alia, starting materials for the preparation of plant protection agents or pharmaceuticals.