Method for producing n-phosphonomethyl iminodiacetic acid

US7084298B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Matthias Maase · Speyer, DE
• Michael Drogemuller · Uelzen, DE

Key dates

• Filing date: Jan 11, 2002
• Grant date: Aug 1, 2006
• Expiry date: Oct 26, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/3808
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for the preparation of N-phosphonomethyliminodiacetic acid by reacting an alkali metal salt of iminodiacetic acid with phosphorus trichloride in aqueous solution with formation of the hydrochloride of iminodiacetic acid, phosphorous acid and of the corresponding alkali metal chloride, followed by reaction with a formaldehyde source and, if desired, recovery of the N-phosphonomethyliminodiacetic acid from the reaction mixture, in which water, which may comprise HCl, is removed from the reaction mixture during and/or after reacting the alkali metal salt of iminodiacetic acid with phosphorus trichloride until the concentration of iminodiacetic acid hydrochloride is at least 40% by weight, based on the weight of the reaction mixture minus the weight of alkali metal chloride.The process makes possible the preparation of N-phosphonomethyliminodiacetic acid in a simple fashion and in high yield.