Method of preparing N-phosphonomethyl glycine

US6121485A · kind A · utility

Assignee

• SKW Trostberg Aktiengesellschaft · DE

Inventors

• Thomas Neumann · Frankfurt am Main, DE
• Frank Fleischer · Palling, DE
• Jurgen Graefe · Trostberg, DE
• Benedikt Hammer · Trostberg, DE

Key dates

• Filing date: Dec 7, 1998
• Grant date: Sep 19, 2000
• Expiry date: Dec 7, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/3813
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

To prepare N-phosphonomethyl glycine, PA1 a) aminomethylphosphonic acid or one of its salts in water, if necessary or desirable with the addition of lyes, is reacted with an alkali carbonate and/or alkali hydrogencarbonate or with carbon dioxide and a lye, PA1 b) the resulting alkali salt of N-phosphonomethylcarbamic acid is subsequently hydroxymethylated with formaldehyde, PA1 c) the salts, resulting from b), of N-hydroxymethyl-N-phosphonomethyl-carbamic acid, if necessary or desirable with addition of a lye, are reacted with hydrocyanic acid and/or a cyanide and PA1 d) the N-carboxy-N-phosphonomethylglyconitrile salts thus obtained are treated with acids and converted by means of hydrolysis and decarboxylation into N-phosphonomethyl glycine. In this way, it is possible to obtain excellent yields of high-purity N-phosphonomethyl glycine.