Process for preparing phosphonous esters

US6090967A · kind A · utility

Assignee

• Clariant Corporation · DE

Inventors

• Sebastian Hörold · Lechenich, DE
• Norbert Weferling · Hürth, DE
• Heinz-Peter Breuer · Hürth, DE

Key dates

• Filing date: Jun 29, 1999
• Grant date: Jul 18, 2000
• Expiry date: Jun 29, 2019

Classification

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

Abstract

The present invention relates to a process for preparing phosphonous esters which comprises PA1 a) reacting elemental yellow phosphorus with alkyl halides in the presence of alkali metal hydroxides and/or alkaline earth metal hydroxides to form a mixture which comprises, as main components, the alkali metal salts and/or alkaline earth metal salts of the alkylphosphonous, phosphorous and hypophosphorous acids, PA1 b) removing the alkylphosphonous acid from the mixture obtained by a) PA1 c) esterifying the alkylphosphonous acid. The invention likewise relates to the use of the phosphonous esters prepared by this process.