Patent GB-733354-A (GB)
Title: Manufacture of cupriferous azo-dyestuffs of the stilbene series
IPC: C09B56/04
Filed: 1952-04-25
Abstract: The invention comprises the manufacture of cupriferous azo dyestuffs of the stilbene series by treating a dyestuff of the general formula <FORM:0733354/IV (c)/1> (wherein R1 represents a benzene residue and R2 and R3 p-phenylene residues, one of the residues R1 and R2 containing a hydroxy group and the other a methoxy or hydroxy group in a position vicinal to the azo linkages connecting them, Z represents an azo or azoxy group (i.e. the group formed by reaction of a nitro group with an amino group in the presence of an alkali metal hydroxide), and R4 represents the residue of a hydroxybenzene-o-carboxylic acid bound to the azo linkage in para-position to the hydroxy group, or the residue of an alkoxybenzene free from carboxylic acid groups), with an agent yielding copper under conditions such that the corresponding o : o1-dihydroxyazocopper complex is formed, the cupriferous dyestuffs so obtainable, and the use thereof in dyeing or printing.  Coppering may be effected with cuprous or cupric salts or with compounds containing copper in complex union, especially copper ammine complexes, advantageously in an aqueous medium and if desired in the presence of suitable additions such as ammonia or organic bases, whilst when one of the groups taking part in the complex formation is a methoxy group it is usually necessary to work at a raised temperature.  When R4 is the residue of a hydroxybenzene-o-carboxylic acid, this is preferably left free from copper, e.g. by coppering in an acid medium, or by using a quantity of copper ammine complex not greatly in excess of that required to introduce a single atom of copper and subjecting the product to a mild treatment in an acid medium to split off any copper combined with the o-hydroxycarboxylic acid grouping.  The products are suitable for dyeing animal fibres and especially cellulosic materials, and may be further metallized on the fibre when they contain uncoppered metallizable groups.  The starting materials may be made by condensing together, advantageously in aqueous caustic alkali, a compound of the formula <FORM:0733354/IV (c)/2> (obtainable by coupling diazotized 4-nitro-41-aminostilbene-2 : 21-disulphonic acid with a hydroxybenzene-o-carboxylic acid capable of coupling in para-position to the hydroxy group, or with a hydroxybenzene free from carboxylic acid groups and capable of coupling, especially in para-position to the hydroxy group, followed in this case by alkylation of the hydroxy group) and an aminodiazo dyestuff of the formula R1-N = N-R2-N = N-R3-NH2 (obtainable by coupling the diazo compound of an amine R1NH2 with a middle component NR2NH2, p rediazotizing and coupling with a middle component HR3NH2).  In examples (1) the sodium salt of the monoazo dyestuff obtained by coupling diazotized 4-nitro-4-aminostilbene-2 : 21-disulphonic acid with phenol and etherifying the product by the action of methyl chloride is refluxed in aqueous caustic soda with the aminodisazo dyestuff 2-aminophenol-4-sulphonic acid --> 2 : 5-dimethoxyaniline --> m-toluidine, and the product is heated with ammoniacal copper sulphate solution and monoethanolamine; the first dyestuff may be ethylated instead of methylated, or the diazo component of the second may be replaced by 4-chloro-2-aminophenol-6-sulphonic acid; (2) the 2 : 5-dimethoxyaniline in the first part of (1) is replaced by m-anisidine or 2-methyl-5-methoxyaniline; in the former case the m-toluidine may also be replaced by 2 : 5-dimethylaniline; (3) the first dyestuff in the first part of (2) is replaced by the dyestuff 4-nitro-41-aminostilbene-2 : 21-disulphonic acid --> 1-hydroxybenzene-2-carboxylic acid or its 6-methyl derivative, and the coppering is followed by warming with a solution of sodium chloride acidified with hydrochloric acid; (4) cotton is dyed an olive tint with the first dyestuff of (1) from a bath containing sodium sulphate. Additional components specified are: diazo components R1NH2 : 2-aminophenol - 4 - sulphonic acid amide, 2 - aminophenol - 4 - sulphonic acid - 6 - carboxylic acid and 2 - aminophenol - 4 : 6 - disulphonic acid, and also, in suitable cases, 2-amino-1-methoxybenzene-4-sulphonic acid and its amide; middle components HR2NH2 : m - aminophenol, 1-amino - 3 - hydroxy - 6 - methylbenzene, and 1-amino - 3 - methoxy - 5 - methylbenzene; middle components HR3NH2 : aniline and 2-methoxy - 5 - methylaniline; coupling components R4H : 6-chloro and 5-methyl-1-hydroxybenzene-2-carboxylic acid, and (subsequently etherified) o-cresol.  Specifications 644,883 and 674,708 are referred to.