Patent GB-719363-A (GB)
Title: Manufacture of metalliferous azo-dyestuffs
Filed: 1952-12-22
Abstract: The invention comprises metalliferous azo dyestuffs of formula:- <FORM:0719363/IV(c)/1> where R1 is a heterocyclic residue having a five-membered hetero-ring containing two hetero-atoms of which at least one is a nitrogen atom bound exclusively in the ring, <FORM:0719363/IV(c)/2> is the residue of a middle component of the benzene or naphthalene series to which the azo linkages are bound in paraposition relatively to one another and the substituent U is bound in ortho-position relatively to the azo-linkage connecting R2 with R3, U is O or -COO of which the carbon atom is bound to R2, <FORM:0719363/IV(c)/3> is the residue of a 1-oxy-naphthalene-3-sulphonic acid bound in the 2-position to the azo linkage and contains in a b -position an amino group, and Me is Ni or Cu.  They may be made by treating a dyestuff of formula <FORM:0719363/IV(c)/4> with an agent yielding nickel or copper under conditions such that an o, o1-dioxy-azo-or o-oxy-o1-carboxy-azo-metal complex is formed, when necessary, with the splitting off of the alkyl group from the group U.  The metal free dyestuffs may be made by coupling, advantageously in a weakly acid to weakly alkaline medium, a diazo compound of R1NH2 with, <FORM:0719363/IV(c)/5> , diazotizing and coupling the diazo-azo-compound with H-R3 -OH in an alkaline medium optionally with the addition of agents such as pyridine or picoline.  Specified initial components which advantageously contain a group imparting solubility e.g. a sulphonic acid group, are 5- or 6-amino-indazole, 6-amino-benzimidazole, 2-methyl-6-amino-benzimidazole, 2-methyl-5-amino-benzimidazole-7-sulphonic acid and 1,2-dimethyl-5-amino-benzimidazole-7-sulphonic acid. Advantageously the initial component contains the diazotizable amino group attached to an aryl nucleus which is bound to the hetero-ring by a simple bound as in 2-(41-aminophenyl)-benzimidazole and its 1-methyl derivative and 2-(41aminophenyl)-benzoxazole and their sulphonic acids.  Other specified initial components are 2- and 6-amino-benzthiazole, 6-amino-2-methylbenzthiazole, 2-aminothiazole, 2-(41- and 31-aminophenyl)-benzthiazole, 2-(41-aminophenyl)-5- and 6-chloro-, 6-methoxy and -ethoxy-benzthiazole and their sulphonic acids preferred being 2-(41-aminophenyl)-6-methyl-benzthiazole and its mono- and di-sulphonic acids.  The middle components are advantageously of the benzene series and contain a methoxy group specified being 2-amino-4-methyl-1-oxybenzene, 2-aminobenzene-1-carboxylic acid, 1-amino-2-methoxy-, 2, 5-dimethoxy- and 2, 5-diethoxy-benzene, 1-amino-2-methoxy - 5-methylbenzene, 1 - amino-2-methoxy and 2-ethoxy-naphthalene and their 6- or 7-sulphonic acids.  Middle components of poor coupling power may be used as their o -methane sulphonic acids.  Specified end components are 2-amino- 2-acetylamino-, 2-benzoylamino-, 2-phenylamino- and 2-(41-carboxymethoxyphenylamino)-5-oxynaphthalene - 7 - sulphonic acid, 2 - amino-, 2 acetylamino-, 2 - benzoylamino-, 2 - b  - oxyethylamino-, 2 - methylamino-, 2 - phenylamino-, 2 - (41-carboxy - methoxyphenyl amino) - and 2 - (N - methyl - phenylamino - 8 - oxynaphthalene - 6 - sulphonic acid, 2-phenylamino-8-oxynaphthalene-6-sulphonic acid-31- or -41-carboxylic acid or 31-sulphonic acid amide, 2-phenylamino-8-oxynaphthalene-6, 31- or -6, 41-disulphonic acid advantageously 2-phenylamino-8-oxynaphthalene-6-sulphonic acids are used in which the phenyl group contains groups such as the sulphonic acid or carboxylic group which impart solubility.  Desirably the disazo-dyestuff contains at least two groups imparting solubility. Metallization is effected in known manner e.g. with salts of divalent nickel or copper in a weakly acid medium or with a nickel or copper tetrammine in the presence or absence of an excess of amine or ammonium or as in Specification 644,883 in the presence of an oxyalkylamine or a copper complex derived therefrom.  The metal dyestuffs may be used for dyeing wool, silk, leather, cotton, linen, artificial silk and regenerated cellulose in grey, blue, green or brown tints.  Examples and a table describe the use of certain of the reagents specified above.