Patent GB-719483-A (GB)
Title: Halo-aliphatic alkylene polyamino acids and method of producing same
Filed: 1952-03-10
Abstract: The invention comprises as new compounds halo-aliphatic alkylene polyamino acids having the formul : <FORM:0719483/IV (b)/1> wherein Z is an acetic or propionic acid residue (-CH2COOH or -CH2.CH2.COOH), X is an aliphatic hydrocarbon group (which may contain an interrupting ether-oxygen atom); Y is halogen; alkylene is ethylene, trimethylene or propylene, n is 1,2,3, or 4; and A is X-Y, hydrogen, an acetic or propionic acid residue, or an alkyl group; and the salts of such acids.  The acids in which Y is chlorine, may be obtained by reacting an aliphatic chlorobromide with an alkylene polyamine polycarboxylic acid in alkaline pH alcohol-water solution maintained at a substantially constant reaction temperature of about 50 DEG  C., cooling and filtering the reaction solution to remove the insoluble constituents present, vacuum distilling the filtered solution at temperatures below 50 DEG  C. to remove the alcohol therefrom, treating the alcohol free solution with a carboxylate type cation exchange resin of the hydrogen form to convert the amino acid salts therein to amino acid (the solution having been sufficiently diluted to minimize absorption of the amino acid), separating the acid solution from the resin and evaporating off the water of solution to recover the chloro-aliphatic alkylene polyamino acid content of the solution. The analogous bromo- and iodo-aliphatic compounds may be prepared from the chloroaliphatic compounds by double decomposition with bromide and iodide compounds in aqueous solution with removal of the chloride ions by ion-exchange reaction with an anion exchange resin or by fractional crystallization of the bromo or iodo compounds from the reaction solution.  In examples: (1) ethylene diamine diacetic acid is reacted with ethylene chlorobromide in accordance with the above described procedure to yield N,N1-di-(2-chloroethyl)-ethylene diamine diacetic acid; the dihydrobromide of the latter rearranges at elevated temperature to yield a substance believed to have the structure: <FORM:0719483/IV (b)/2> which on dissolving in water and neutralizing is converted to diethanol ethylene diamine diacetic acid; (2) the disodium salt of ethylene diamine diacetic acid is dissolved in water and treated with an alcoholic solution of 1-chloro-2-(b -bromoethoxy)-ethane, the product being isolated from the reaction mixture by absorption on a strong cation exchanger in a suitable column which is then eluted with ammonia solution to yield N,N1-di-(2-chloroethoxyethyl)-ethylene diamine diacetic acid which is stated to be useful for deactivation of non-aqueous phases such as synthetic resins and rubber; (3) trimethylene diamine diacetic acid is reacted with ethylene chlorobromide and the product isolated as in (2) to yield N,N1-di-(2-chloroethyl)-trimethylene diamine diacetic acid. Propylene chlorobromide and trimethylene chlorobromide may be used in the examples instead of ethylene chlorobromide to give analogous products.  It is stated that the reaction may be used to extend the length of the polyamine chain in a polyamino polycarboxylic acid having at least one free hydrogen on a terminal amino group, thus triethylene tetramine tetraacetic acid may be converted to a higher amine by reacting its sodium salt with ethylene chlorobromide to yield the sodium salt of N,N111 - di - (2 - chloroethyl) - triethylene tetramine - N,N1,N11,N111 - tetraacetic acid which may be converted to the free acid or reacted with an appropriate amine or alkylene polyamine to produce the desired higher amine.  By using one half of the amount of the aliphatic chlorobromide used in the examples the assymetric monohalide compound may be obtained.  The products are stated to have utility as metal ion chelating agents in aqueous and non-aqueous media.