GB697480A - Manufacture of monoazo-dyestuffs - Google Patents

Abstract

2 : 3 - Oxynaphthoic - 21 : 61 - dimethylanilide is made by condensing 2 : 3-oxynaphthoic acid or its halide with 2 : 6-dimethylaniline. If the acid is used, a phosphorus halide is added, an example of this method being given. The zinc chloride double salt of the diazonium chloride from 4-benzoylamino-2 : 5-dimethoxyaniline is described and also the diazoamino compound from the latter and N-methyltaurine (sodium salt).ALSO:The invention comprises azo dyes of the formula <FORM:0697480/IV (c)/1> where n is 0 or 1 and the nucleus I may contain non-solubilizing substituents. They are prepared in substance or on the fibre from 2 : 3-oxynaphthoic 21 : 61-dimethylanilide and a diazotized 4-benzoylamino-2 : 5-dimethoxyaniline or 4-phenoxyacetylamino -2 : 5-dimethoxyaniline. When prepared on the fibre, e.g. by printing, the paste may contain the diazo component in a stabilized form and urea may be added. In the examples (1) 4-benzoylamino - 2 : 5 - dimethoxyaniline is diazotized and coupled with 2 : 3 - oxynaphthoic 21 : 61 - dimethylanilide; (2) cotton is grounded with a solution of the arylide in caustic soda and Turkey red oil and developed with diazotized 4 - benzoylamino - 2 : 5 - dimethoxyaniline; (3) cotton is grounded as in (2), dried and printed with the zinc chloride double salt of 4-benzoylamino - 2 : 5 - dimethoxybenzene diazonium chloride together with starch-tragacanth thickener; (4) cotton is printed with a paste of the arylide, the diazoamino compound from diazotized 4 - benzoylamino - 2 : 5 - dimethoxyaniline and N-methyltaurine (sodium salt), Turkey red oil, alcohol, caustic soda and starch-tragacanth thickener; it is then dried, developed by acid steaming, the starch removed by enzymes and the print soaped; the alcohol may be replaced by thiodiglycol and urea added. The following 4 - acylamino - 2 : 5 - dimethoxyanilines are also specified as diazo components:-o-, m- and p - toluylamino, p - tert - butylbenzoylamino, o-, m - and p - chlorobenzoylamino, o -, m - and p - fluorobenzoylamino, o - and p - anisoylamino, o - and p - ethoxybenzoylamino, phenoxyacetylamino and p - tolyloxyacetyl - amino. Specification 303,838, [Class 15 (ii)], and U.S.A. Specification 1,871,946 are referred to.