Patent GB-606872-A (GB)
Title: Manufacture of new substantive azo-dyestuffs
IPC: C09B45/18
Filed: 1946-02-11
Abstract: 2-Aminophenols containing in the 4- or 6-position a group -CONHR (wherein R represents an alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical, which may contain substituents), but otherwise unsubstituted, are prepared by condensing a primary amine (e.g. aniline, 2-chloro-, 2-methoxy-, 4-ethoxy-or 4-methylaniline, a - or b -naphthylamine, benzylamine, ethylamine, ethanolamine, butylamine, cyclohexylamine, 2-aminothiazole, 6-methoxy-2-aminobenzthiazole or 2-(41-aminophenyl)-6-methylbenzthiazole) with 1-hydroxy-2-nitrobenzene-4- or -6- carboxylic acid in the presence of an agent capable of removing water, or with the corresponding acid chlorides, followed by reduction of the nitro group. Specifications 12250/15, 12932/15, [both in Class 2 (iii)], and 601,266, [Group IV (c)], are referred to.  The Specification as open to inspection under Sect. 91 comprises also the preparation of similar compounds in which the benzene nucleus contains further substituents, e.g. from 1-hydroxy-2-nitro-6-chlorobenzene-4-carboxylic acid, 1-hydroxy-2 : 4-dinitrobenzene-6-carboxylic acid or 1-hydroxy-2-nitro-6-bromobenzene-4-carboxylic acid or their chlorides.  This subject-matter does not appear in the Specification as accepted.ALSO:Azo dyestuffs suitable for dyeing cellulose are manufactured by coupling in an alkaline medium a diazotized 2-aminophenol containing in the 4- or 6-position a group -CONHR (wherein R represents an alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical, which may contain substituents) but otherwise unsubstituted, with 2 : 5 : 7-aminonaphtholsulphonic acid or an N-substitution product thereof, and, if desired, treating the product with an agent-yielding metal, especially copper.  Dyeings with the non-metallized dyestuffs may be coppered on the fibre, in the dyebath or a separate bath, e.g. by treatment with copper sulphate at a raised temperature, or with copper salts in the presence of water-soluble condensates of formaldehyde with compounds such as melamine or dicyandiamidine, or, in an exhausted dyebath, with complex compounds of copper salts with aliphatic hydroxycarboxylic acids, such as tartaric acid.  Suitable diazo components are those in which R is phenyl, 2-chloro-, 2-methoxy-, 4-ethoxy- or 4-methylphenyl, a - or b -naphthyl, benzyl, ethyl, hydroxyethyl, butyl, cyclohexyl, 2-thiazyl, 6-methoxy-2-benzthiazyl or p-(6-methyl-2-benzthiazyl)-phenyl. Suitable coupling components are: 2 : 5 : 7-acid itself, its N-acyl derivatives (e.g. its N-acetyl-, benzoyl-, 21 : 41-dichlorobenzoyl- and p-methoxybenzoyl-derivatives and its urea), its N-alkyl (e.g. ethyl and b -hydroxyethyl) and N-aryl (e.g. phenyl and substituted phenyl, e.g. p-chloro-, p- or m-carboxy-, 41-hydroxy-31-carboxy-, p-sulpho- and p-methoxyphenyl) derivatives, 5 : 51-dihydroxy-2 : 21-naphthylamine-7 : 71-disulphonic acid, N : N1-ethylene-bis-(2 : 5 : 7- acid), and reaction products of heterocyclic compounds containing reactive halogen atoms with 2 : 5 : 7-acid, e.g. of 1 mol of cyanuric chloride with 1 mol each of 2 : 5 : 7-acid and aniline, or with 2 mols of 2 : 5 : 7-acid, or with 1 mol each of 2 : 5 : 7- and 2 : 8 : 6- acids, or with 2 mols of 2 : 5 : 7- acid and 1 mol of aniline, or with 1 mol each of 2 : 5 : 7- acid, aniline and 1-amino-4-hydroxybenzene-3-carboxylic acid or 4-amino-41-hydroxy-1 : 11-azobenzene-31-carboxylic acid.  Examples are given of the production of dyestuffs from some of the foregoing components and of the dyeing of cotton with certain of the products. Specifications 12,250/15, 12,932/15, [both in Class 2 (iii)], and 601,266 are referred to. p  The Specification as open to inspection under Sect. 91 comprises also the use of diazo components of the kind defined above in which the benzene nucleus contains further substituents, e.g. the N-monosubstituted amides of 1 - hydroxy - 2 - amino - 6 - chlorobenzene - 4 - carboxylic acid, 1-hydroxy-2-amino-4-nitrobenzene-6-carboxylic acid or 1-hydroxy-2-amino-6-bromobenzene-4-carboxylic acid. 2-carboxyethylamino-5-naphthol-7-sulphonic acid is additionally specified as a coupling component.  This subject-matter does not appear in the Specification as accepted.