GB564024A - Manufacture and use of tetrakisazo-dyestuffs - Google Patents

Abstract

Tetrakisazo dyes are obtained by tetrazotising a diaminodisazo compound of the general formula <FORM:0564024/IV/1> wherein R represents a benzene or naphthalene residue, w represents a group NH2 (derived by reduction of a group NO2 or saponification of a group NHAcyl) in m- or p-position to the azo group, two x's represent H and the third represents a residue of the general formula <FORM:0564024/IV/2> wherein y represents H or alkoxy and one z represents H and the other H or SO3H, and coupling with resorcinol or m-aminophenol (2 mols.). The products give on fibres of natural or regenerated cellulose dark dyeings of which the shades and the fastness to wet treatments may be improved by after-treatment with formaldehyde or with a diazo compound. In some cases the dyeings are dischargeable. Specified nitro and acylamino components are 3- and 4-nitroanilines and their 6-methyl and 6-methoxy derivatives, 3- and 4 - acetylaminoanilines, 4 - oxalylaminoaniline, 2-methyl-4-acetylaminoaniline, 2 : 5-dimethyl-4-acetylaminoaniline, 3-acetylamino-4-methoxyaniline and sulphonic acids thereof, and 1-amino-4 - nitro- or acetylamino - naphthalene - 6 or 7-sulphonic acids, and specified 1-aminonaphthalene components are 1-aminonaphthalene itself and its 2-methoxy- and 2-ethoxy derivatives and their 6- or 7 - sulphonic acids. Examples relate to the production of the dyestuffs: (1) resorcinol or 3-aminophenol \sM 1 : 4 - diaminobenzene (from 4 - acetylaminoaniline) --> (alkaline) 1 : 5 : 7-, 2 : 5 : 7- or 2 : 8 : 6 - acid --> 1 - aminonaphthalene --> resorcinol or 3-aminophenol; the 1 : 4-diaminobenzene may be replaced by its 2-methyl- or 2 : 5-dimethyl-derivative (from the 4-acetylamino compound); (2) resorcinol \sM 1 : 4-diaminonaphthalene - 6 - sulphonic acid (from the 4-acetylamino compound) --> (alkaline) 2 : 5 : 7- or 2 : 8 : 6-acid --> 1-aminonaphthalene or its 2-methoxy- or 2-methoxy-6-sulphonic acid derivative --> resorcinol; (3) resorcinol \sM 1 : 4-diaminobenzene (from 4-oxalylaminoaniline) --> (alkaline) 2 : 5 : 7-acid --> 1 - amino - 2 - methoxynaphthalene or its 6-sulphonic acid --> resorcinol; (4) resorcinol \sM 1 : 4-diaminobenzene (from 4-acetylaminoaniline) --> (alkaline) 2 : 5 : 7-acid --> 1-aminonaphthalene-6-sulphonic acid --> resorcinol; (5) resorcinol \sM 1 : 3-diaminobenzene (from 3-oxalylaminoaniline) --> (alkaline) 1 : 5 : 7-, 2 : 5 : 7- or 2 : 8 : 6-acid --> 1-aminonaphthalene --> resorcinol. Examples are also given of the dyeing process for cotton with (a) development with diazotised 4-nitroaniline, (b) development with aqueous formaldehyde. 2 : 5-Dimethyl-4-acetylaminoaniline is obtained by reducing the nitro group in the product of successive acetylation and nitration of 2 : 5-dimethylaniline. 3-Acetylamino-4-methoxyaniline is obtained by reducing the nitro group in the product of acetylation of 5-nitro-2-methoxyaniline.