GB615210A - Manufacture of disazo-dyestuffs containing copper in complex union - Google Patents

Abstract

Diazo dyestuffs containing copper in complex union are manufactured by coupling one molecular proportion of tetrazotized dianisidine in an alkaline medium with (a) two molecular proportions (the same or different) of an acylaminonaphthol-mono- or -di-sulphonic acid other than N-acyl-1 : 8 : 2 : 4-acid, or (b) one molecular proportion of a coupling component as under (a) and one of a coupling component of another kind containing a hydroxy or enolizable keto group and capable of coupling in o-position in respect thereto and free from -NH2 groups, or of 1 : 8-aminonaphthol-2 : 4-disulphonic acid, heating the product with an ammoniacal solution of copper sulphate until the methoxy groups have been split up, and hydrolysing the acylamino group or groups, without destroying the copper complex, by treatment with a dilute solution of an alkali or of a mineral acid. Suitable coupling components are, on the one hand, N-formyl, -acetyl and -propionyl derivatives of aminonaphtholsulphonic acids, and the corresponding carbramic ester (N-carbalkoxy) derivatives and, on the other hand naphthol-mono- or disulphonic acids, hydroxy compounds of the benzene series and pyrazolone compounds. In examples, the following dyestuffs are prepared and heated with ammoniacal copper sulphate solution and then with 3-4 per cent caustic soda solution or, in some cases, alternatively with 3-4 per cent mineral acid solution: (1) dianisidine-->two molecular proportions of N-acetyl- or N-carbethoxy-1 : 8-aminonaphthol-3 : 6-disulphonic acid or N-acetyl - 2 : 8 : 3 : 6 -, 2 : 5 : 7- or 3 : 5 : 7-acid; (2) N-acetyl - 1 : 8 : 3 : 6- acid\sMdianisidine-->1 - naphthol - 4 - sulphonic or - 3 : 6 - disulphonic acid, 2 - phenylamino - 5-naphthol - 7 - sulphonic acid, 1 - (41 - sulphophenyl) - 3 - methyl - 5 - pyrazolone, resorcinol, 1 : 8 : 2 : 4 - acid or 2 - naphthol - 4 - sulphonic acid. The products dye cotton from an alkaline bath in various tints of blue. Additional coupling components specified are N-acetyl-1 : 8 : 4 : 6- acid and N-carbethoxy-2 : 5 : 7-acid.