Patent GB-586411-A (GB)
Title: Process for the manufacture of new stilbene dyestuffs
IPC: C09B56/04
Filed: 1945-01-09
Abstract: Stilbene dyestuffs are manufactured from 4 : 41-dinitro-stilbene- or -dibenzyl-2 : 21-disulphonic acid, or from 4-nitrotoluene-2-sulphonic acid or the dyestuffs obtainable therefrom by treatment with caustic alkali solutions, by condensing these compounds in the presence of caustic alkali, if desired under pressure, with aromatic compounds containing the group <FORM:0586411/IV/1> , wherein X represents an alkyl or substituted alkyl group and Y represents hydrogen or an acyl radical capable of being replaced by hydrogen by the action of caustic alkali, e.g. secondary amines formed by the introduction of groups such as -CH3, -C2H5, -CH2CH2OH, -CH2CH(OH)CH2OH, CH2COOH, -CH2 CH2SO3H or -CH2CH(OH)CH2SO3H into the amino group of aromatic amines or aminoazo dyestuffs such as aniline, toluidines, 2 : 4- or 2 : 5-dimethylanilines, anisidines, m- or p-phenylenediamine, 1 - amino - 3 - methoxy - 6 - methylbenzene, 1 - amino - 2 : 5 - dimethoxy - benzene or the naphthylamines, heterocyclic alkylamine compounds such as alkylaminodiaryltriazoles, their sulphonic and carboxylic acids, or azo dyestuffs containing secondary amino groups obtainable by coupling secondary amines containing a free p-position with diazo compounds from aminobenzenesulphonic acids or their substitution products, o-aminocarboxylic acids or o-aminophenolsulphonic acids, by coupling monoalkylarylamines containing a carboxylic or sulphonic acid group in the alkyl residue with diazotized unsulphonated amines or aminophenols, or by coupling N-monoalkylaminonaphtholsulphonic acids in alkaline solution with diazotized amines or aminophenols. These compounds may be used singly or mixed, and may be partly replaced by compounds containing primary amino groups.  The products may be subjected to after-treatment with oxidizing or reducing agents.  When the compounds containing the group <FORM:0586411/IV/2> contain metallizable groups, they may be used in the form of their metal complexes, or the dyestuffs obtained from the corresponding metal-free compounds may be after-treated with metal-yielding agents. In examples: (1) 4 : 41-dinitrostilbene-2 : 21-disulphonic acid sodium salt is refluxed with N-methylaniline in aqueous caustic soda solution, and, if desired, the product is reduced by means of alkaline glucose solution; the N-methylaniline may be replaced by N-b -hydroxyethyl-N-b  : g -dihydroxypropyl-, N - b -sulphoethyl- or N-g -sulpho-b -hydroxypropyl-aniline, or phenylglycine, or the corresponding alkyl derivatives of the toluidines, 2 : 4- or 2 : 5-dimethylaniline, the anisidines or the naphthylamines, and the stilbene compound by the corresponding dibenzyl derivative; (2) the N-methylaniline in (1) is replaced by the azo dyestuff aniline --> phenylglycine; the product may be reduced by means of glucose in alkaline solution, or a similar result may be obtained by carrying out the condensation under pressure at 110-115 DEG  C., if desired with excess of the aminoazo dyestuff, which may be replaced by dyestuffs from diazotized aromatic amines and second amines with a free p-position and containing a sulphonic acid group in the alkyl group; (3) the azo dyestuff sulphanilic acid --> N-methylaniline is treated as in (2); reduction of the product may also be effected with sodium sulphide in alkaline solution; (4) the azo dyestuff metanilic acid --> 1-b -hydroxyethylamino - 2 - methoxybenzene is treated as in (1); the product may be purified by the action of sodium hypochlorite in alkaline solution; (5) the azo dyestuff 2-amino-1-methoxybenzene - 4 - sulphonic acid --> 1 - methylamino - 3 - methoxybenzene is similarly treated; (6) the azo dyestuff 2-aminophenol-4-sulphonic acid --> 1-methylamino-3-methoxybenzene is treated as in (1); the product may be converted by the action of ammoniacal copper sulphate solution into a difficultly soluble copper compound, from which an easily soluble compound is obtainable by splitting off methylamine by heating to 90 DEG  C.; the 1-methylamino-3-methoxybenzene may be replaced by the glycine of 1-amino-3-methoxy-6-methylbenzene or of 1-amino-2 : 5-dimethoxybenzene; (7) the azo dyestuff in (6) is replaced by a mixture thereof with 4-amino-1 : 11-azobenzene-41-sulphonic acid in various proportions; the first of these aminoazo compounds may be wholly or partly replaced by corresponding dyestuffs from a 1-monoalkylamino-3-methoxy-6-methylbenzene or a 1-monoalkylamino-2 : 5-dimethoxybenzene, and the second by analogous dyestuffs from various diazotized aniline- or a -naphthylamine-sulphonic acids and o- or m-toluidine, p-xylidine, o- or m-anisidine, cresidine, 2 : 5-dimethoxyaniline or a -naphthylamine; (8) the azo dyestuff 1-amino-4-(N-methyl)-acetyamino-2-methoxy- (or 2 : 5-dimethoxy-) benzene --> 2-naphthol-4-sulphonic acid is treated as in (1).