Patent GB-680779-A (GB)
Title: Manufacture and use of new derivatives of azo-dyestuffs
IPC: C09B43/18
Filed: 1950-07-20
Abstract: The invention comprises acylated azo dyestuffs of the formula <FORM:0680779/IV (c)/1> where R1 is a cyclic residue condensed on to the benzene nucleus, R2 is a diazo residue free from acylamino groups and A is a furane or thiophene nucleus; there are no solubilizing groups apart from those shown.  These are made by treating dyestuffs of the formula <FORM:0680779/IV (c)/2> with two mols. of a monohalide of a furane or thiophene sulphocarboxylic acid (see Specification 679,698, [Group IV (b)], which may be prepared in situ.  The products have the above formula whether the halide is the carboxylic halide or sulphonic halide.  The acylated derivatives are hydrolysed back to the parent dyestuffs by alkali.  Thus they may be used to dye or print textiles (especially of animal fibres such as wool) from acid to neutral solutions; after-treatment of the fibre with dilute alkali then regenerates the insoluble pigment.  Hydrolysis may also be effected by longer treatment at a raised temperature in a neutral to acid medium.  In the examples: (1) the dyestuff 1 - naphthylamine --> 2 : 3 - oxynaphthoic anilide is heated with furane-2-carboxylic acid-5-sulphonic acid, p-toluenesulphochloride and pyridine; (2) as in (1) using the disodium salt of the acid; (3) the dyestuff 3-chloraniline --> 2 : 3-oxynaphthoic o-toluidide is heated with the monosodium salt of the acid of (1), pyridine and phosgene; (4) the dyestuff 2 : 5-dichloraniline --> 2 : 3-oxynaphthoic o-anisidide is heated with the acid of (1), pyridine and phosgene or p-toluenesulphochloride; (5) the dyestuff 2 : 5-dichloraniline --> 2 : 3-oxynaphthoic o-phenetidide is heated with the acid of (1), pyridine, p-toluenesulphochloride and triethylamine; (6) the dyestuff 2 : 5-dichloraniline --> 2 : 3-oxynaphthoic o-aniside is heated with thiophene-2-carboxylic acid-5-sulphonic acid, pyridine and phosgene; (7) as in (1) using triethylamine instead of pyridine; (8) the dyestuff 5-chlor-o-toluidine --> 3 :2-oxydiphenylene oxide carboxylic acid 21 : 51-dimethoxyanilide is heated with p-toluenesulphochloride and pyridine; (9) the dyestuff 1-naphthylamine --> 2 : 3-oxynaphthoic anilide is heated with furane-2-carboxylic acid-5-sulphochloride and pyridine; (10) as in (9) using furane-2-carboxylic acid chloride-5-sulphonic acid; (11) the dyestuff 3-chloraniline --> 2 : 3-oxynaphthoic o-toluidide is heated with disodium 5-chlorfurane-2-carboxylate - 3 - sulphonate, p - toluenesulphochloride and pyridine; (12) as in (11) using the corresponding 5-bromofurane derivative; (13) the dyestuff 3-chloraniline --> 2 : 3-oxynaphthoic o-toluidide is heated with the disodium salt of the acid of (1), p-toluenesulphochloride and pyridine; (14) as in (11) using the corresponding 3 : 4-dichlorfurane derivative; (15) the dyestuff 3-chloraniline --> 2 : 3-oxynaphthoic o-toluidide is heated with the acid of (1), p-toluenesulphobromide and pyridine; (16) wool is dyed in an acid bath with the product of (4) and the dyeing developed with ammonia, followed by soaping with a wetting agent; (17) cotton is printed with a paste containing the product of (4), thiodiglycol and starch-tragacanth thickening; the print is developed with ammonia, malted and soaped.  A table is given of further acylated dyestuffs and additional groups are specified for R2 and "Aryl" in the above formul .  The ring-system formed by R1 and the benzene ring of the formul  may be naphthalene, diphenylene oxide or carbazole.  Specifications 480,358, 482,184 and 512,664 also are referred to.