GB347288A - Process for the manufacture of azo dyestuffs - Google Patents

Abstract

Monoazo dyes soluble in water are made by coupling aromatic diazo compounds with aminonaphthols containing one or more unsubstituted or substituted sulphamino residues or derivatives thereof in acid or alkaline solution. They yield fast clear dyeings on wool, are suitable for manufacture of pigments, and some dye acetate silk. The following are specified: (1) aniline-2-sulpho acid, 4-toluidine-3-sulpho acid or 4-acetylamino-1-aminobenzene-2-sulpho acid --> 1-acetylamino-8-naphthol - 3 : 6 - disulphodi - (N - methylanilide); (2) aniline-2-sulphonic acid or 2-aminophenol-4-sulpho acid --> 1-amino-8-naphthol-3 : 6-disulphanilide; other o-aminophenolsulpho acids, e.g. chloro or nitro derivatives may be used and also the N-methyl- or N-ethylanilides or 1-acetylamino-8-naphthol-4 : 6-disulpho-di-(N-methylanilide); (3) 3-nitraniline-6-sulpho acid or aniline-2-sulphonic acid --> 2-amino-8-naphthol-6-sulpho-N-ethylanilide; other aminosulpho- or carboxy acids may be used, e.g. chloraniline sulpho acids or 4-acetylamino-1-aminobenzenesulpho acids; (4) aniline-2 : 5 or 2 : 4-disulpho acid, 3-nitraniline-4 : 6-disulpho acid or 2-amino-41-hydroxy-31-carboxydiphenylsulphone-4 -sulphonic acid (cf. Specification 245,865, [Class 2 (iii), Dyes &c.]), --> 2-amino-8-naphthol-6-sulpho-N-methylanilide; 2-amino-21-hydroxy-31-carboxy-51-methyldiphenyl sulphone-4-sulpho acid (cf. Specification 297,855, [Class 2 (iii), Dyes &c.]), --> the N-ethyl- or N-hydroxyethyl compound; 41-hydroxy-31- carboxy-2-amino-5 -acetylaminodiphenylsulphone (cf. Specification 267,366, [Class 2 (iii), Dyes &c.]), 2-amino-8-naphthol-6-sulpho - (41 - hydroxy-31 - carboxyanilide); (5) 4-chloro-2-aminophenol-6-sulphonic acid --> 2-amino-5-naphthol-7-sulphanilide; other o-aminophenol or o-aminonaphthal sulpho or carboxy acids or o-aminophenol-sulphamides may be used as diazo components and the corresponding amide, methylamide, cyclohexylamide, benzylamide, methylanilide and piperidide as coupling components; (6) 2-aminophenol-4-sulphamide --> 2-amino-5-naphthol-7-sulphodi-methylamide; (7) 6-nitro-2-aminophenol-4-sulphonic acid --> 2-amino-8-naphthol-6-sulphanilide; (8) 2-nitraniline-4-sulphonic acid --> 2-amino-8-naphthol-6-sulpho-N-methylanilide; (9) 5-nitro-2-amino-1-methoxybenzene-4-sulphonic acid --> 2-amino-8-naphthol-6-sulpho-N-ethylanilide, N-hydroxyethylanilide or dimethylamide; (10) 1-amino-4-acetylaminobenzene-2-sulphonic acid --> 2-amino-8-naphthol-6-sulpho-N-hydroxyethylanilide (barium lake specified); (11) o-toluidine-p-sulpho acid --> 1-acetylamino - 8 - naphthol - 3 : 6 - disulphodi - (N - methylanilide) (pink on acetate silk). Dyeings from dyestuffs containing suitable groups may be after-chromed. Aminonaphtholsulphonic acid amides are made from the sulphochlorides of Specification 326,226, [Class 2 (iii), Dyes &c.], by treating with ammonia or a suitable base. Those amides not substituted in the amino group are made from the corresponding substituted compounds by saponification with acids or alkalies.