Process for the preparation of alkylphosphonous acid diesters and/or dialkylphosphinous acid esters

US5128495A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Gunter Scheffel · Burghausen, DE
• Michael Thiele · Wien, AT

Key dates

• Filing date: Apr 5, 1990
• Grant date: Jul 7, 1992
• Expiry date: Apr 5, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/48
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The said compounds are prepared by reaction of trialkyl phosphites with phosphorus trichloride and/or dichlorophosphinous acid monoalkyl esters at -20 to +100.degree. C. and direct subsequent reaction with alkylmagnesium chloride or alkylmagnesium bromide at -60 to +50.degree. C. and subsequent separation of the desired compounds from the distillate of the volatile compounds. Dialkyl alkylphosphonites and monoalkyl dialkylphosphinites are thus obtained without troublesome and expensive purification of intermediates. The phosphorus-containing esters produced are, for their part, useful intermediates, for example for the preparation of flame retardants and plant protection agents.