Patent ID: 9556378
Date: 2017-01-31
CPC Classifications: C07C,C09K

Claim:
1. Chelating agent precursor of the chelating agents glutamic acid N,N-diacetic acid (GLDA) and/or methylglycine N,N-diacetic acid (MGDA), wherein at least one of the carboxylic acid groups is present as a carboxylic acid derivative selected from the group consisting of anhydrides, esters, combinations thereof, and salts thereof, provided that it is not the triethyl ester of GLDA, the triethyl mono-t-butyl ester of GLDA, the tri-t-butyl ester of GLDA, the monobenzyl tri-t-butyl ester of GLDA, any ester that contains azacycloalkane groups, (S)-diethyl 2,2′-(1-benzyloxy)-1,5-dioxo-5-(prop-2-ynylamino)pentan-2-ylazanediyl-diacetate, diethyl 2,2′-(5-(3-azidopropylamino)-1-(benzyloxy)-1,5-dioxo-pentan-2-ylazanediyl-diacetate, the trimethyl ester of MGDA, the monomethyl ester dimethylamide of MGDA, the dibenzyl ester of MGDA, the dibenzyl mono t-butyl ester of MGDA, the di t-butyl ester of MGDA, the di-t-butyl-monobenzyl ester of MGDA, and esters of GLDA immobilized on a gel, wherein, when the carboxylic acid derivative is an ester, it is an ester of an alcohol selected from the group of aliphatic alcohols containing 1 to 12 carbon atoms that optionally may contain additional hydroxyl, amine and/or ether groups, and wherein, when the carboxylic acid derivative is an anhydride, it is an anhydride of a carboxylic acid selected from the group consisting of fatty acids and aliphatic carboxylic acids containing 1 to 12 carbon atoms that optionally may contain additional hydroxyl, amine, carboxylic acid and/or ether groups.