Patent GB-706380-A (GB)
Title: Manufacture of new disazo-dyestuffs
IPC: C09B43/12
Filed: 1952-05-19
Abstract: The invention comprises disazo dyestuffs containing two or three sulphonic acid groups and of the general formula <FORM:0706380/IV(c)/1> (wherein the -OC- and -NH- groups in the nucleus I are in meta- or para-position to one another, R1 represents a p-phenylene residue and R2 the residue of a 1-hydroxybenzene-2-carboxylic acid bound in 4-position to the azo linkage, one of the residues R1 and R2 containing a sulphonic acid group and both optionally containing further substituents, and X represents a -CO- group or a residue of the formula <FORM:0706380/IV(c)/2> where Y represents a halogen atom, or a hydroxy, amino or substituted amino group), and the manufacture thereof by reacting aminomonoazo dyestuffs of the general formulae <FORM:0706380/IV(c)/3> and <FORM:0706380/IV(c)/4> with phosgene or a cyanuric halide, the third halogen atom in the latter case being subsequently replaced, if desired, by a hydroxy, amino or substituted amino group, especially a group -NHAr where Ar is a benzene residue which may contain a sulphonic acid group. The phosgenation is advantageously effected in an aqueous medium, preferably with the dyestuffs in the form of their alkali metal salts and with the addition of an acid-binding agent to buffer the reaction mixture to about pH 5.5-9.5.  When using a cyanuric halide, the two or three condensations may be conducted successively in an aqueous medium with progressive raising of the pH value or the temperature or both. Preferred aminomonoazo dyestuffs of type (B) are those of the general formula <FORM:0706380/IV(c)/5> (wherein Z1 and Z2 each represent hydrogen, methyl or methoxy, or Z2 may also represent halogen).  The products are suitable for dyeing or printing cellulose materials, and may be treated on the fibre or partly on the fibre and partly in the dyebath with agents yielding metal.  In examples: (1) 4\sv-(4"-amino)-benzoylamino - 2\sv - chloro - 4 - hydroxy-1 : 1\sv-azobenzene-3-carboxylic acid-5-sulphonic acid and 4\sv-amino-2\sv-chloro-4-hydroxy-1 : 1\sv-azobenzene-3-carboxylic acid-5-sulphonic acid are treated with phosgene in an aqueous solution of sodium carborate and acetate; the first dyestuff may be replaced by the corresponding 3"-amino compound; (2) the dyestuffs of the first part of (1) are successively reacted with cyanuric chloride, and the product may be hydrolysed with alkali or reacted with aniline or its 3- or 4- sulphonic acid; (3) the second dyestuff in (1) is replaced by 4\sv-amino-4-hydroxy-1 : 1\sv-azobenzene-3-carboxylic acid-2\sv- or 3\sv-sulphonic acid or the 5-methyl derivative of the former, or (4) by 4\sv-amino-4-hydroxy-1 : 1\sv-azobenzene-3-carboxylic acid-5-sulphonic acid or its 2- or 3-methyl or -methoxy, 2 : 5-dimethyl- or -dimethoxy, or 2-methyl-5-methoxy derivative; (5) cotton is dyed yellow with the first product of (1) from a bath containing sodium carbonate and sulphate with after-treatment in the same bath with complex sodium copper tartrate.  Specifications 455,274 and 619,969 are referred to. Monoazo dyestuffs.-The starting materials of the general formula (A) above are obtainable by coupling a diazotized 1-amino-2-chloro-4-nitrobenzene with salicylic acid, sulphonating the product, reducing the nitro group to an amino group, acylating this with m- or p-nitrobenzoyl chloride and reducing the nitro group.  The preparation of the first starting material of example (1) above is described in detail.  The starting materials of the general formula (B) are obtainable as follows (a) when the sulphonic acid group is in R2, by coupling diazotized 4-aminophenol-2-carboxylic acid-6-sulphonic acid with a para-coupling amine of the benzene series (e.g. aniline, o-, or m-toluidine, o- or m-anisidine, 2 : 5-dimethyl- or -dimethoxy- or 2-methoxy-5-methyl-aniline), or with the o -methanesulphonic acid thereof with subsequent hydrolysis; (b) when the sulphonic acid group is in R1, by coupling a diazotized p-nitranilinesulphonic acid with an o-hydroxybenzoic acid in alkaline solution and then reducing the nitro group; (c) 4\sv-amino-4-hydroxy - 1 : 1\sv-azobenzene-3-carboxylic acid-3\sv-sulphonic acid by coupling 1-amino-4-diazobenzene-2-sulphonic acid with salicylic acid in alkaline solution.