GB358483A - Process for the manufacture of azo dyestuffs - Google Patents

Abstract

Monoazo dyes are obtained by coupling a sulphonated aromatic diazo compound, other than an o-oxydiazo compound, with a 1-naphthol-3 : 6-disulphonamide or an N-substituted derivative or an 8-halogen derivative thereof or with a 1-naphthol-3 : 7-disulphonamide or an N-substituted derivative thereof. The products yield clear even dyeings, fast to light, washing, and fulling, on wool and are suitable for the manufacture of lakes and for printing. The following examples are specified (1) The dyestuff, aniline - 2-sulphonic acid -->-1-naphthol-3 : 6-disulphonic acid-di-(N-methyl-anilide), dyes wool a clear even orange fast to fulling and light; the corresponding products having as diazo components 4-methyl-1-aminobenzene-2-sulphonic acid 4-methoxy 1-aminobenzene-2-sulphonic acid, and 4-acetylamino-1-aminobenzene-2-sulphonic acid dye wool similar blueish red shades. (2) The dyestuff, 4-methyl-1-aminobenzene-2-sulphonic acid --> 1-naphthol-3 : 6-disulphonic acid-dianilide, dyes wool an even yellowish red, fast to fulling and light; similar dyestuffs are obtained with the use as diazo components of other aminosulphonic acids of the benzene series containing no o-oxyamino group and with the use as coupling components of the corresponding chloranilides and toluidides. (3) The dyestuff, 4-chloro-1-aminobenzene-2-sulphonic acid --> 1-naphthol-3 : 6-disulphonic acid di-(N-b -hydroxyethyl-anilide), dyes wool a very even yellowish red fast to light and fulling; similar dyestuffs are obtained with the use as diazo components of other aminosulphonic acids of the benzene series containing no o-oxyamino group, e.g. 4-methyl-1-aminobenzene-2-sulphonic acid and 4-acetylaminobenzene-2-sulphonic acid. (4) The dyestuff, 4-methyl-1 - aminobenzene - 2 - sulphonic acid- --> 1-naphthol-3 : 6-disulphonic acid-di-(31-acetylaminoanilide), dyes wool a clear, very even, yellowish red, very fast to light and fulling; similar dyestuffs are obtained with the use as diazo components of other aminosulphonic acids of the benzene series containing no o-oxyamino-group and with the use as coupling component of 1-naphthol-3 : 6-disulphonic acid-di- (41-acetylaminoanilide). (5) The dyestuff, 4-methyl - 1 - aminobenzene- 2- sulphonic acid --> 8-chloro-1-naphthol-3 :6-disulphonic acid-dianilide, dyes wool a very even clear red, fast to fulling and light. (6) The dyestuffs, 1-amino-2-ethoxynaphthalene-6 - sulphonic acid --> 1 - naphthol-3 : 6-disulphonic acid-di- (31 [or 41]-acetylaminoanilide), dye wool very even clear violet shades fast to washing and fulling. (7) The dyestuff, 4-acetylamino-1 - aminobenzene - 2-sulphonic acid --> 1-naphthol-3 : 7-disulphonic acid-dianilide dyes wool an even blueish red fast to fulling, washing, and light. 1-Naphthol-3 : 6 (or 3 : 7)-disulphonamides and their N-substituted derivatives are obtained by heating the 1-naphthol-3 : 6 (or 3 : 7)-disulphochlorides with ammonia or the corresponding amines in presence of an acid-binding agent, e.g. sodium acetate. 8-chloro-1-naphthol-3 : 6-disulphonic acid-dianilide is obtained according to the process described in Specification 232,620, [Class 2 (iii), Dyes &c.].