Patent GB-718509-A (GB)
Title: Manufacture of new imino-dicarboxylic acids and functional derivatives thereof
Filed: 1951-06-13
Abstract: Imino-dicarboxylic acids of the general formula <FORM:0718509/IV (b)/1> R being an aromatic residue which may contain further substituents, x = 1 or 2, y is 1-4, at least one OH being ortho to the alkylimino group or functional derivatives of such acids, are obtained by reaction between a compound (HO)1-3R-(CH2hl)y and an imino-dicarboxylic acid <FORM:0718509/IV (b)/2> or a salt or derivative thereof.  Products of the above formula may also be obtained by reaction between an aromatic compound substituted by not more than three OH groups and having a hydrogen atom in ortho-position to at least one OH group and an imino-dicarboxylic acid as above in either order, with formaldehyde or a derivative thereof.  The same products may also be obtained by reaction of aromatic compounds having not more than 3 OH groups and more than 4 -CH2OH groups, one being ortho to an OH group, with the abovementioned imino-dicarboxylic acids or derivatives thereof.  The reacting compounds referred to may have further substituents.  As imino dicarboxylic acids imino-dipropionic acids and iminodiacetic acid are referred to, and their nitriles, esters or salts may be used.  Compounds containing phenolic hydroxy groups and two methyl imino-dicarboxylic groups may be obtained.  In examples, imino-diacetic acid reacts with formaldehyde and: phenol, p-cresol, 2 : 4-dichlorophenol, 4-octadecylphenol, pyrocatechol, p-acetylaminophenol, o-acetylamino-p-cresol and phenol-p-sulphonic acid; and with di-oxymethyl-p-cresol to give the corresponding substituted hydroxy benzylaminodiacetic derivatives, y being 1 or 2 according to the proportions employed; similarly the dimethyl ester of iminodiacetic acid reacts with 2 : 6-dichloromethyl-p-cresol, 4-nitro-2-chloro-methyl-phenol (the nitro-product being subsequently reduced to amino-) and 2 : 6-di-methylol-4-methyl-phenol to give the corresponding substituted hydroxy benzylamino-diacetic acids on hydrolysis; p-cresol reacts with formaldehyde and imino-dipropionic acid to give a product having two imino-dipropionic groups.  The aromatic compounds may have in addition to those exemplified, numerous substituents.  The products form complex metal compounds with copper, chromium, calcium and other metals, those forming complexes with calcium being useful for dispersing or dissolving lime soaps and those containing higher alkyl residues may be used for soaps and softening agents resistant to weak acids.  Complex copper, zinc and mercury salts are useful fungicides and bactericides. Specification 474,082 is referred to.ALSO:Aralkyl-iminodiacetic and imino-dipropionic acids having one or more OH groups in the phenyl radical, at least one OH group being ortho to an imino group (see Group IV(b)), form complex compounds with calcium ions, and can be used as agents for the dissolution of lime soaps and for inhibiting the formation of lime soaps.  In examples, the products obtained by the action of p-cresol, phenol, 2:4-dichlorophenol, pyrocatechol and phenol-p-sulphonic acid with formaldehyde on iminodiacetic acid are shown to have good dissolution action on prepared dispersions of lime soaps. Specification 474,082 is referred to.