Patent GB-674708-A (GB)
Title: Manufacture of new cupriferous azo dyestuffs of the stilbene series
Filed: 1950-07-28
Abstract: The invention comprises cupriferous dye-stuffs of the formula <FORM:0674708/IV (c)/1> in which the group -U-Cu-U- is bound to R1 and R2 in positions vicinal to the azo group, one U representing oxygen and the other oxygen or -COO- bound to Cu by -O-; R1, R2 and R3 are aromatic residues of not more than 10 carbon atoms in the nuclei, R3 being free from hydroxy groups, Z is azo or azoxy and R4 is an organic residue bound by an aromatic nucleus direct to Z. These are made by coppering the corresponding dyestuffs where R1 and R2 contain an o : o1-dihydroxy, o-hydroxy-o1-methoxy or o-hydroxy-o1-carboxy grouping.  Coppering may be effected with copper salts such as cuprous chloride or cupric sulphate or with cuprammine complexes, e.g. with ammonia, ethylamine or other alkylamine, morpholine, pyridine or piperidine.  Ammonia or an organic base may be added, e.g. ethanolamine as in Specification 644,883.  The products can be used for dyeing and printing animal and cellulosic fibres, e.g. wool, leather, linen, cotton and artificial silk.  The parent metal-free dyestuffs are obtained by condensing 4 : 41-dinitrostilbene-2 : 21-disulphonic acid with an aminodyestuff <FORM:0674708/IV (c)/2> or with a mixture of this and another amine R4NH2 which may or may not be an azo dyestuff; thus the products are respectively symmetrical or unsymmetrical.  The condensation is preferably carried out by heating with aqueous alkali hydroxide. When unsymmetrical dyestuffs are to be formed the condensation with the two amines may take place successively.  The amino - disazo dyestuffs <FORM:0674708/IV (c)/3> may be made by coupling diazotized R1NH2 with a middle component H-R2NH2, diazotizing the product and coupling with a further middle component H-R3NH2. Such components may be used as their -NH-CH2-SO2H derivatives which are hydrolysed after coupling. The amine R4NH2 may be the same or a different amino-disazo dyestuff, or an aminomonoazo dyestuff or an amine such as aminocinnamic acid or dehydrothiotoluidine mono- or di-sulphonic acid.  Also, it may be a triazolostilbene of the formula <FORM:0674708/IV (c)/4> or <FORM:0674708/IV (c)/5> If R4NH2 is an amino-monazo dyestuff it may be prepared by coupling diazotized metanilic acid, sulphanilic acid, o-anisidine or its p-sulphonic acid, p-aminocinnamic acid, dehydrothiotoluidine mono- or di-sulphonic acid, 1-naphthylamine-4 : 7-disulphonic acid, 2-naphthylamine-4 : 8-disulphonic acid or one of the above triazolo-stilbenes with aniline, m-toluidine, p-xylidine or 1-naphthylamine.  In the examples: (1) 4 : 41-dinitrostilbene-2 : 21-disulphonic acid is condensed with 2 mols. of the disazo dyestuff 2-aminophenol-4 : 6-disulphonic acid (or -4-sulphonic acid-6-carboxylic acid) --> m-anisidine --> m-toluidine, and the product coppered with cuprammonium sulphate with ethanolamine; (2) as above, using 1 mol. of the disazo dyestuff o-anisidine-4-sulphonic acid --> J acid --> m-toluidine, and 1 mol. of the monoazo dyestuff 2-napthylamine-4 : 8-disulphonic acid; (3) using 2 mols. of the disazo dyestuff 2-aminophenol-4-sulphonic acid --> J acid --> m-toluidine; (4) using 1 mol. of the disazo dyestuff 2-amino-4-chlorophenol-6-sulphonic acid --> J acid --> m-toluidine and 1 mol. of the disazo dyestuff dehydrothiotoluidine-disulphonic acid --> p-xylidine --> p-xylidine; (5) using 1 mol. of the disazo dyestuff 2-methoxy-4-nitraniline --> 1-naphthol-3-sulphonic acid (reduced) --> m-toluidine and 1 mol. of the monoazo dyestuff 2-naphthylamine-4 : 8-disulphonic acid --> p-xylidine; (6) using 1 mol. of the disazo dyestuff 2-amino-4-chlorophenol-6-sulphonic acid --> J acid --> p-xylidine and 1 mol. of the triazolo-stilbene of the second formula above (-5-, -6-, -7-sulphonic or -5 : 7-disulphonic acid in the naphthalene nucleus).  Ethanolamine is used for coppering only in example (1).  A table is given of further components which may be condensed with 4 : 41-dinitrostilbene-2 : 21-disulphonic acid, and an example is given of the dyeing of cotton with the product of example (2).  Specified substituents on the nuclei are:- R1: hydroxy, methoxy, carboxylic acid, sulphonic acid, sulphonamide, chlorine and acetyl; R2: hydroxy, methoxy, carboxylic acid, nitro (reduced for next diazotization and coupling with R3), methyl, sulphonic acid; R3: methyl, methoxy, sulphonic acid.  The triazolo-stilbene of the second formula above is made by coupling diazotized 4-nitro-41-aminostilbene-2 : 21-disulphonic acid with 2-naphthylamine-6-sulphonic acid, reducing the nitro group to amino and oxidizing the product.