Process for the preparation of vinylphosphonic dichloride

US4761252A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Herbert Siegel · Hofheim, DE
• Erwin Weiss · Hofheim, DE
• Harald Berger · Kelkheim, DE

Key dates

• Filing date: Aug 27, 1987
• Grant date: Aug 2, 1988
• Expiry date: Aug 27, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/42
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the preparation of vinylphosphonic dichloride, in which a 2-chloroethanephosphonate of the formula ##STR1## or a mixture of the two esters, is reacted with thionyl chloride at a temperature of 60.degree. to 160.degree. C. in the presence of a catalyst which contains tertiary phosphines, quaternary ammonium or phosphonium salts or alkali metal or alkaline-earth metal halides. During this reaction, any thionyl chloride which may be present is removed by distillation subsequent to this reaction, the mixture remaining is heated to 140.degree. to 200.degree. C., and the vinylphosphonic dichloride produced during this is removed by distillation.