GB786567A - Metallisable heterocyclic azo dyestuffs - Google Patents

Abstract

The invention comprises dyestuffs which contain the group <FORM:0786567/IV (b)/1> where the N atom o to O.B.X.Y. is in a heterocyclic ring, B is CO or SO2, X is a bridging group containing a cyclic residue and Y is COOH, SO3H or a quaternary ammonium group of the form -N(tert)anion. They are made by treating the corresponding hydroxy compounds with an acylating agent derived from an acid HO.B.X.Z. where Z is COOH, SO3H, a quat. amino group or an halogen atom not directly attached to an aromatic nucleus, and when Z is a tert. amino group or halogen atom subsequently converting them to a quat. ammonium group. Such agents include acid halides which are used in conjunction with bases such as pyridine, triethylamine and alkali and alkaline earth metal hydroxides and carbonates. Organic solvents such as dimethyl formamide may be present. Acylations with agents where Z contains an halogen atom not directly attached to an aromatic nucleus are preferably effected in a tertiary amine which acts both as an acidbinding agent and to convert the product to a quaternary ammonium salt. Dyestuffs where Y is CO2H or SO3H may also be made by treating the above hydroxy compounds with an appropriate acid or salt thereof, in the presence of a tertiary amine such as pyridine, and a reactant capable of forming an halide of the acid, e.g. phosgene and an halide of an aromatic sulphonic acid such as p-toluene-sulphonyl chloride, and optionally in an organic solvent, preferably an amide, such as dimethyl formamide. When an acid of formula HO.CO.X.SO3H is used the halide formed may be either a carboxylic acid or a sulphonyl halide. Specified bridging members are -C6H4-, -C4H2O- and -C4H6-CH2-. The hydroxyl-containing dyestuffs used as starting materials may be made by coupling diazotized primary aromatic amines with appropriate coupling components such as 8-hydroxyquinoline, 1-hydroxyacridine and 4-hydroxy-benzthiazole. Specified amines are aniline, p-nitroaniline, benzidine, diamidine, 4,41-diamino-benzene, -benzanilide, -diphenylamine and diphenylurea, 31,4-diamino-3,41-dimethoxybezanilide and 1,5-diaminonaphthalene. A preferred class of dyestuffs is derived from compounds of formula: <FORM:0786567/IV (b)/2> where A is a direct link or a bridging group such as -N=N-, -CONH-, NH or -NH-CO-NH- and where the nuclei may contain further groups such as alkoxy groups. The dyestuffs dye cellulosic fibres by the alkaline after-coppering process when preferably the dyestuffs contain no water-solubilizing groups other than -O.B.X.Y. The group B.X.Y. is removed during coppering. When -B.X.Y. contains a quat. ammonium group the dyestuffs are especially useful since they exhibit a very high degree of exhaustion from the dye bath. Examples are provided illustrating the preparation of the dyestuffs from certain of the above specified reactants and their use in dyeing cellulosic fibres by after-coppering processes in red and yellow shades. In the Provisional Specification -CH2- and -CHClare additional bridging groups. Specification 761,776 is referred to.