Conversion of hydroxymethyl-iminodiacetic acid to phosphonomethyl-iminodiacetic acid
AssigneeHampshire Chemical Corp.
InventorBarry A. Cullen
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Abstract
A process for preparing N-phosphonomethyl iminodiacetic acid wherein solutions of an alkali metal salt of IDA are reacted with formaldehyde so as to form the alkali metal salt of hydroxymethyliminodiacetic acid (HMIDA). The HMIDA can be subsequently reacted with a phosphorous source such as phosphorous acid to produce PMIDA in good yield.
Claims12
A process for the preparation of a stable, storable solution of an alkali metal salt of hydroxymethyl-iminodiacetic acid, comprising reacting an alkali metal salt of iminodiacetic acid with a formaldehyde source selected from the group consisting of formaldehyde, paraformaldehyde, formalin and trioxane.
A process for the preparation of phosphonomethyl-iminodiacetic acid, comprising:
- a. reacting an alkali metal salt of iminodiacetic acid with a formaldehyde source selected from the group consisting of formaldehyde, paraformaldehyde, formalin and trioxane to form a stable, storable solution of the alkali metal salt of hydroxymethyl-iminodiacetic acid;
- and
- b. reacting the reaction product of step a with a phosphorus source selected from the group consisting of PCl.sub.3 and H.sub.3 PO.sub.3 and a strong acid having a pK.sub.a less than or equal to about 2.
Dependencies are inferred from the claim text.