GB427241A - The manufacture of dyestuffs - Google Patents

Abstract

Dyestuff corresponding to the general formula <FORM:0427241/IV/1> in which X=azo or azoxy, R=a radicle of the benzene or naphthalene series which may be connected with further radicles or the whole radicle attached on the other side to X, and R1=a radicle of the naphthalene series which may contain further substituents or may be connected with further radicles, are made by oxidizing in alkaline solution a stilbene compound of the general formula <FORM:0427241/IV/2> in which Y=NO2, arylazo or arylazoxy, and in cases in which Y=NO2 subsequently converting the same into an arylazo or arylazoxy group. They dye vegetable fibres yellow to red to brownish shades fast to light. In examples: (1) the dyestuff 4-nitro-4<1>-aminostilbene-2 : 2<1>-disulphonic acid --> 2-naphthylamine is oxidized with ammoniacal copper sulphate to the triazole which is condensed with dehydrothiotoluidinemono- or di-sulphonic acids in caustic soda solution; o-coupling naphthylamine sulphonic and carboxylic acids may also be used; (2) the above triazole is condensed with the azo dye anthranilic acid --> (alk.) J acid; the product may be after-treated in substance or on the fibre with copper salts; (3) the dyestuff 4-nitro-4<1>-aminostilbene-2 : 2<1>-disulphonic acid --> 2-naphthylamine-6-sulphonic acid is reduced with alkaline glucose to the azo- or azoxy-compound and the product oxidized to the triazole with sodium carbonate and copper sulphate; aminonaphthal sulphonic acids, e.g. J acid and \su-acid may be used in place of the 2-naphthylamine and the resulting products may be coupled with diazo compounds containing metal complex forming groups forming dyes which may be after-coppered; (4) the methylated and reduced dyestuff 4 - nitro - 4<1> - aminostilbene - 2 : 2<1> - disulphonic acid --> phenol is diazotized, coupled in acid medium with J acid, oxidized to the triazole as above, and coupled with diazotized 4-nitro-2-amino-1-anisole; the copper compound dyes cotton reddish brown. Specifications 403,105 and 404,613 are referred to.