GB344250A - Improvements in the manufacture and production of azo dyestuffs - Google Patents

Abstract

Monoazo dyes and soluble metal compounds thereof; acid wool dyes, dyeing with.-Monoazo dyes are obtained by coupling diazo compounds with amides of 5-pyrazolone-3-carboxylic acids; the latter may be substituted in the 1-position of the pyrazolone ring and in the amide NH2 group. Certain of the products, e.g. those obtained from o-oxydiazo compounds may be converted in substance or on the fibre into complex metal compounds by treatment with agents yielding metals. The following examples are specified. (1) The dyestuff aniline --> 1 - (41-sulpho) phenyl-5-pyrazolone-3-carboxylic acid amide dyes wool and silk level powerful golden yellow shades of good fastness. (2) The dyestuff 4-nitro-2-aminophenol-6-sulphonic acid --> 1 - (41-sulpho) phenyl-5-pyrazolone-3-carboxylic acid amide dyes wool red-brown shades which on after-chroming become very fast red-orange; the chromium compound prepared in substance gives very uniform orange-brown dyeings on wool. (3) The dyestuff 1 : 2 aminonaphthol-4-sulphonic acid --> 1-phenyl-5-pyrazolone-3-carboxylic acid anilide dyes wool brown-red shades which on after-chroming become very fast violet. (4) The dyestuff 4-nitro-2-aminophenol-6-sulphonic acid --> 1phenyl-5-pyrazolone-3-carboxylic acid amide dyes wool red-brown shades which on after chroming become very fast brown; the chromium compound prepared in substance gives very fast uniform red-orange dyeings on wool. 1-(41-Sulpho) phenyl-5-pyrazolone-3-carboxylic acid amide and 1-phenyl-5-pyrazolone-3-carboxylic acid amide are obtained by the action of ammonia on the corresponding carboxylic acid ethyl esters. 1-Phenyl-5-pyrazolone-3-carboxylic acid anilide is obtained by the action of aniline on the corresponding carboxylic acid chloride.