GB972955A - New heterocyclic dyes - Google Patents

Abstract

The invention comprises dyes of formula <FORM:0972955/C4-C5/1> wherein Z is a divalent radical which may contain one or more hetero atoms, necessary for the completion of a 5- or 6-membered ring which may bear fixed rings and may be substituted, R1 is a hydrogen atom or an alkyl radical which may be substituted, a cyclohexyl, benzyl or phenyl radical, R2 is an alkyl radical which may be substituted, A is a divalent radical completing a substituted or unsubstituted 5- or 6-membered mono- or poly-nuclear heterocyclic ring system, X is a formly, carboxylic acid, carboxylic acid ester, carboxylic acid hydrazide, a substituted or unsubstituted carboxylic acid amide, a carboxylic thioamide group or an acyl group of an aliphatic or aromatic carboxylic acid, E is the equivalent of an anion, m is 1 or 2 and n is 1 or 2. The dyes are prepared by (a) coupling a diazo compound of an amine of formula <FORM:0972955/C4-C5/2> with a heterocyclic methylene compound of formula <FORM:0972955/C4-C5/3> or (b) reacting a hydrazone of formula <FORM:0972955/C4-C5/4> with a heterocyclic methylene compound as specified above in the presence of a dehydrogenating or oxidizing agent. The dyes so prepared may be subsequently alkylated. The dyes may be used to colour mordanted cotton, leather, cellulose ethers and esters, polyamides, polyurethane, polyester and, in particular, polyacrylonitrile materials in yellow and red shades. In examples, dyes wherein the ring <FORM:0972955/C4-C5/5> is a benzthiazole, thiodiazole, indazole, thiazole or triazole ring and the heterocyclic methylene compound is a benzimidazole, or indoline derivative are specified.