Salts, crystals, complexes, and derivatives of threonine diacetic acid, a process to prepare threonine diacetic acid, and the use thereof

Patent metadata

Field	Value
Publication number	US-9416095-B2
Application number	US-201414905432-A
Country	US
Kind code	B2
Filing date	Jul 11, 2014
Priority date	Jul 16, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

The present invention relates to new salts, complexes, crystals, solutions, dispersions, and slurries of threonine-N,N-diacetic acid or derivatives thereof, to formulations containing those, to processes to prepare those, and to the use thereof.

First claim

The invention claimed is:

1. A process to prepare threonine-N,N-diacetic acid or a salt thereof comprising two or more steps wherein in a first step threonine, a sodium or potassium salt thereof or a mixture thereof is reacted with formaldehyde and hydrogen cyanide, at a pH equal to or below 7 to form a nitrile compound, and in a second step the nitrile compound formed in the first step is hydrolyzed by the addition of an acid or base.

2. A process to prepare threonine-N,N-diacetic acid or a salt thereof comprising reacting threonine, a sodium or potassium salt thereof or a mixture thereof with formaldehyde, hydrogen cyanide, a potassium or sodium salt thereof or a mixture thereof, and potassium hydroxide, sodium hydroxide or a mixture thereof, in an aqueous solution at an alkaline pH and at an elevated temperature to remove formed NH 3 .

3. A process to prepare threonine-N,N-diacetic acid or a salt thereof, wherein threonine is reacted with a monohaloacetic acid at a temperature of 20 to 80° C. and an alkaline pH.

4. The process of claim 1 wherein said nitrile compound is threonine-N,N-diacetonitrile or a salt thereof.

5. The process of claim 1 wherein subsequent to the hydrolysis step an acidification step is performed.

6. The process of claim 2 wherein subsequent to the reaction at alkaline pH an acidification step is performed.

7. The process of claim 3 wherein said monohaloacetic acid is monochloroacetic acid.

8. The process of claim 3 wherein the reaction product is a salt of threonine-N,N-diacetic acid and a subsequent acidification step is performed to convert the salt formed into the acid.

9. A composition comprising a compound selected from the group consisting of
a complex of threonine-N,N-diacetic acid and a divalent or trivalent cation, wherein the cation is selected from the group of calcium, magnesium, iron, zinc, manganese, aluminium, copper, and cobalt; and
a salt of threonine-N,N-diacetic acid of the formula CH 3 —CHOH—C(H)(COOM)-N—(CH 2 —COOM) 2 , wherein at least one M is chosen from the group of sodium, potassium, lithium, cesium, and ammonium.

10. The composition of claim 9 wherein said compound is in crystalline form.

11. The composition of claim 9 wherein said composition is a formulation comprising a liquid.

12. The composition of claim 11 wherein the liquid is water.

Assignees

• Akzo Nobel Chemicals Int Bv

Inventors

• Carstens Axel
• Boonstra Tjerk Oedse
• Zaitsev Alexey Borisovich
• Heus Martin
• Veenis Wouter Jan

Classifications

• C07C253/00

  Preparation of carboxylic acid nitriles (of cyanogen or compounds thereof C01C3/00) · CPC title

• C07C227/18 Primary

  by reactions involving amino or carboxyl groups, e.g. hydrolysis of esters or amides, by formation of halides, salts or esters · CPC title

• C07C229/16

  to carbon atoms of hydrocarbon radicals substituted by amino or carboxyl groups, e.g. ethylenediamine-tetra-acetic acid, iminodiacetic acids · CPC title

• C11D3/33

  Amino carboxylic acids · CPC title

• C07C227/16

  by reactions not involving the amino or carboxyl groups · CPC title