METHOD OF PRODUCING ALKYLENE AMINOPOLYCARBOXYLIC ACIDS Russian patent published in 2013 - IPC C07C227/04 C07C229/16 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing alkylene aminopolycarboxylic acids, particularly N-carboxyethyl and N-carboxymethyl derivatives of N₁N¹-bis(piperazinoethyl)ethylenediamine, which can be used as complexing agents. Disclosed is a method of producing alkylene aminopolycarboxylic acids by reacting hexamine with acrylonitrile at 60-65°C in molar ratio of hexamine to acrylonitrile equal to 1:2-4 for 4-6 hours; treating the reaction mass with concentrated hydrochloric acid at 90-98°C in molar ratio of hexamine to HCl equal to 1:6-8 for 6-8 hours; and reacting hexamine with monochloroacetic acid at 80-85°C in molar ratio of hexamine to monochloroacetic acid equal to 1:2-4 for 4-6 hours; the reaction mass is treated with excess alkali to obtain the product. The method also includes versions of successive reaction of hexamine with acrylonitrile, then with monochloroacetic acid, or hexamine with monochloroacetic acid and then with acrylonitrile. The alkali used is a 36-46% solution of sodium or potassium hydroxide.

EFFECT: simple process and high output of the end product.

2 cl, 1 tbl, 6 ex