METHOD OF PRODUCING ETHYLENEDIAMINE-N,N'-DI-α-PROPIONIC ACID Russian patent published in 2015 - IPC C07C229/16 C07C227/18 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing ethylenediamine-N,N'-di-α-propionic acid of general formula HOOC(H₃C)HCHNCH₂CH₂NHCH(CH₃)COOH. According to the disclosed method, the feed stock used is ethylenediamine and α-chloropropionic acid. The latter in the form of an aqueous solution is pre-treated with calcium oxide to establish pH 9-11. Ethylenediamine is then added in an amount which corresponds to molar ratio of α-chloropropionic acid to the ethylenediamine of 2.1-2.2:1. The feed stock is mixed at 65-70°C in the presence of calcium oxide to maintain pH of the reaction mass at 9-11. The reaction mass is then cooled to 50-55°C, acidified with hydrochloric acid to pH 1.5-2.0 and cooled to 5-10°C. The precipitate is filtered out, dissolved in water and then treated at 5-10°C with triethylamine to establish pH 4.7-5.0. The end product is separated by filtering.

EFFECT: invention increases purity of the end product.

3 cl, 3 dwg, 3 ex