Patent GB-843003-A (GB)
Title: Improvements relating to alkylene or cycloalkylene diamine diacetic acids, their heavy metal complexes and their use
IPC: C07C229/38
Filed: 1956-12-04
Abstract: The invention comprises heavy metal complex-forming compound of the general formula:  <FORM:0843003/IV(b)/1> wherein A represents an o-hydroxy-phenyl radical which is substituted in the p-portion with regard to the hydroxyl group, preferably by an alkyl, carboxyl or sulphonic acid group, or which is condensed at this p-position and at an m-position with another aromatic ring Y represents a carboxymethyl group in its free or salt form and Z represents an alkylene or cycloalkylene radical bound at two adjacent carbon atoms with the nitrogen atoms and heavy metal complexes thereof, a process for the preparation of complex forming compounds of the above general formula characterised in that one mol of a dimethylol compound of the general formula:  <FORM:0843003/IV(b)/2> wherein the symbols Y and Z have the meanings given above is condensed with 2 mols of a hydroxy compound of the general formula: A-H wherein A has the meaning given above; a modification of the process for the production of such compounds characterised by condensing two mols of a chloromethyl compound of the general formula: A-CH2-Cl with one mol of a diamino compound of the general formula:  <FORM:0843003/IV(b)/3> to form a compound of the general formula:  <FORM:0843003/IV(b)/4> wherein A represents an o-hydroxy-phenyl radical which is substituted in the p and o positions with regard to the hydroxyl group, preferably by alkyl, carboxylic or sulphonic acid groups and Y and Z have the meanings given above, and a process for preparation of heavy metal complexes of the compounds of the first formula given above, characterised by treating such compounds or their soluble salts with compounds containing heavy metal, preferably soluble heavy metal salts.  The term "heavy metal" is intended to mean a metal with an atomic number from 24 to 28, iron manganese, nickel cobalt and chromium being mentioned specifically.  In examples: N,N1-bis-(2-hydroxy-3,5-dimethylbenzyl)-ethylenediamine diacetic acid is produced by heating disodium ethylene diamine diacetate with formalin in the presence of water and methanol and reacting the product with 2,4-dimethyl phenol to obtain the disodium salt of the desired acid which is converted to the free acid; N,N1-bis-(2-hydroxy-3,5-dimethylbenzyl)-cyclohexhylene-1, 2-diamine diacetic acid is prepared in an analogous manner starting from disodium N,N1-dicarboxymethyl-cyclohexane-1, 2-diamine formaldehyde and 2,4-dimethylphenol (1); N,N1-bis-(2-hydroxy-5-methylbenzyl)-ethylene diamine diacetic acid and N,N1-bis-(2-hydroxy - 5 - methylbenzyl) - cyclopentylene -1,2-diamine diacetic acid (2), N,N1-bis-(2-hydroxy-5-t-butylbenzyl)-ethylenediamine diacetic acid (3), N,N1 - bis - (2 - hydroxy - 5 - sulphobenzyl) - disodium ethylenediamine diacetate (4), N,N1-bis - (2 - hydroxy - 5 - methylbenzyl) - dipotassium ethylene diamine diacetate (5), N,N1-bis-(2-hydroxy - 5 - carboxybenzyl) - ethylene - diamine diacetic acid (6) and N,N1-bis-(2-hydroxy-5-octylbenzyl)-ethylene diamine diacetic acid (7) are prepared by analogous processes, paraformaldehyde being employed instead of formalin in (5); N,N1 - bis - (2 - hydroxy - 5 - methyl - 3 - sulphobenzyl)-ethylene diamine diacetic acid is obtained by reacting disodium ethylene-diamine diacetate with the sodium salt of 2-hydroxy-3-chloromethyl-5-methyl-benzene sulphonic acid and treating the tetra-sodium salt obtained with acetic acid (8); the iron chelate of N,N1-bis-(2-hydroxy-5-methylbenzyl)-ethylene diamine diacetic acid is obtained by treating the disodium salt with caustic soda and ferric chloride; similar complexes are obtained using manganese sulphate or cobalt nitrate (9); the iron chelate of N,N1 - bis - (2 - hydroxy - 5 - sulphobenzyl)-tetrasodium ethylene diamine diacetate is similarly prepared.  Other phenols may be employed in processes analogues to (2) e.g. p-dodecylphenol An ammonium ethylenediamine diacetate may be employed as starting material to obtain ammonium salt as product.  The iron complexes of the present invention may be employed in treating iron chlorosis in plants growing in alkaline soil.  A table is furnished showing the uptake of iron from alkaline soils treated with radioactive iron containing complexes prepared from the chelating compounds of the invention and known chetaling agents.