GB443242A - Improvements in and relating to the manufacture of azodyestuffs - Google Patents

Abstract

Copper complex compounds of azo dyes are made by treating with an agent yielding copper under conditions such that the two alkoxy groups are split up, the dyes obtained by reducing in a caustic alkaline medium with grape sugar a monoazo dyestuff of the general formula <FORM:0443242/IV/1> wherein R1 may be substituted and R2=the residue of the naphthalene or carbazole series containing at least one SO3H group. The products which are probably disazoazoxy dyestuffs yield redder shades on cotton and regenerated cellulose. In examples: (1) the dyestuff 5-nitro-2-amino-1-methoxybenzene --> 1-naphthol-3 : 6-disulphonic acid is reduced and coppered with ammoniacal copper sulphate; 8-chlor-1-naphthol-3 : 6-disulpho acid, 1-naphthol-3 : 8-disulphonic acid and 5-nitro-4-chloro-2-amino-1-methoxybenzene may also be used as components; (2) the dyestuff 5-nitro-2-amino-1-methoxybenzene --> (alkaline) 2-(4<1>-or 3<1>-carboxyphenylamino)-8-naphthol-6-sulphonic acid is treated as above; N-(3<1>-sulphophenyl) 2 : 8 : 6-acid, N-(3<1>-carboxy-phenyl)-J acid or 2-amino-5-naphthol-1 : 7-disulpho acid; (3) and (4) the dyestuffs 5-nitro-2-amino-1-methoxybenzene --> 2-naphthol-5 : 7-, 3 : 6- or 3 : 7-disulpho acid, 1-hydroxycarbazole-3 : 6-disulphonic acid or 1 : 8- or 2 : 8-dihydroxycarbazole - 3 : 6 - disulphonic acid are similarly treated. The Specification as open to inspection under Sect. 91 refers also to the use of functional equivalents of glucose, such as arsenious oxide and formaldehyde as reducing agents and states that the coppering may take place at higher temperatures and under pressure. The ammonia may be replaced by pyridine or other organic base and the reaction may also be performed in acid medium, e.g. with copper sulphate and sodium acetate. This subject-matter does not appear in the Specification as accepted.