GB794135A - Water-insoluble monoazo dyestuffs containing cyanogen groups - Google Patents

Abstract

The invention comprises dyestuffs of formula: <FORM:0794135/IV (b)/1> where Ar is a benzene or naphthalene residue, R is H, lower alkyl, lower hydroxy alkyl or acylated hydroxy lower alkyl, R1 is H or acyl, the azo bridge and the amino group being in pposition to each other and the nucleus containing the nitrile group is substituted by alkyl and/or halogen and/or nitrile groups, the dyestuffs being free of SO3H and COOH groups. The hydroxy alkyl group may be attached to Ar to form a ring. The invention is restricted to alkyl groups of 1-4 carbon atoms. The dyestuffs are made by coupling appropriate diazotized cyanoanilines with the desired amines of the benzene or naphthalene series. The dyestuffs may be acylated and N-hydroxyalkyl groups present may be esterified. Orange to blue dyeings are obtained on polyamide and cellulose acetate fibres. In examples illustrative of the preparation of the dyestuffs and their use in dyeing polyamide and cellulose rayon fibres the diazo components used are 2-cyano-5 - chloro -, 4 - cyano - 3 - chloro -, 2,4 - dicyano -, 2 - methyl - 4,6 - dicyano - and 2,4-dicyano - 3,6 - dimethylanilines, the coupling components being 3-methyl-, 3-methyl-N-hydroxyethyl -, ethyl - and butyl -, 2 - methyl-5 - ethoxy -, 2,5 - dimethyl - and N - hydroxyethyl - anilines, 6 - and 7 - hydroxy and 2-ethoxy - 1 - naphthylamines and py - tetrahydro - 3,61 - dihydroxy - 7,8,11,21 - benzoquinolines and some of the dyestuffs containing N-hydroxyethylamino groups are treated with acetic anhydride. Specifications 537,831, [Group IV], and 602,878 are referred to.