GB744406A - Manufacture of azo-dyestuffs - Google Patents

Abstract

4 - Nitro - 41 - aminostilbene - 2,21 - disulphonic acid is diazotized and treated with cuprous chloride and hydrochloric acid to yield the corresponding 41-chloro-compound which is then reduced by the Bechamp method to 4 - amino - 41 - chlorostilbene - 2,21 - disulphonic acid. The product is used in the preparation of stilbene azo dyestuffs (c.f. Group IV (c)).ALSO:The invention comprises dyestuffs of formula <FORM:0744406/IV(c)/1> where R1 is the residue of a middle component and R2 is the residue of an aminonaphthol sulphonic acid bound to the azo group in ortho position to the oxy group and complex metal compounds of such dyestuffs as contain in R1 in a position vicinal to the azo linkage between R1 and R2 a group capable of metallization. The dyestuffs are made by coupling in an alkaline medium an aminonaphthol sulphonic acid with a diazo compound obtained by coupling diazotized 4-amino-41-chlorostilbene-2, 21-disulphonic acid with a middle component advantageously in an acid to neutral medium. Especially valuable dyestuffs may be made by diazotizing the stilbene sulphonic acid, coupling with a 1 - amino - 2 - alkoxynaphthol - sulphonic acid, diazotizing the amino-azo dyestuff thus obtained and coupling with a 1-acylamino-8-naphthol-3, 6-disulphonic acid. Specified middle components are 1-amino-2-methoxy-naphthalene and -benzene, 1-amino-2-methoxy-5-methyl- and -2, 5-dimethoxy-benzene and 1-amino-2-methoxy- and -ethoxy-naphthalene-6- and -7-sulphonic acid. End components indicated are 2-acyl- or -aryl-amino-5-naphthol-7-sulphonic acids, 2-amino-8-naphthol 6-sulphonic acid, 1-amino-8-naphthol-3, 6-disulphonic acid, 2-phenyl-, -(41-carboxymethoxy-phenyl)-, -benzyl- and -(41-chlorobenzyl)-amino -5- naphthol -7- sulphonic acid. Nickel and especially copper are specified metals metallization being effected in known fashion, in substance or on the fibre. The metallized and unmetallized dyestuffs dye and print wool, silk, leather and particularly cellulose fibres such as cotton, linen, artificial silk and regenerated cellulose fibres, the coppered dyestuffs yielding green and blue tints on cotton. Examples illustrate the use of certain of the above specified components in the preparation of the dyestuffs additional end components used being 2-acetylamino-5-naphthol-7-sulphonic acid, 1-benzoylamino-8-naphthol-3, 6-disulphonic acid and 2-phenylamino-8-naphthol-6-sulphuric acid-31-carboxylic acid. Specification 644,883 is referred to.