GB744829A - Manufacture of azo-dyestuffs of the stilbene series - Google Patents

Abstract

The invention comprises monoazo and disazo stilbene dyes, wherein at least one of the azo linkages is para to the -CH=CH- bridge and is linked to an 8-oxyquinoline residue, and wherein the stilbene residues contain sulpho groups in 2 and 21- positions. They are made (1) from 4 : 41 - diaminostilbene - 2 : 21 - disulphonic acids by diazotization and coupling at least once with an 8 - oxyquinoline, (2) from 4 - aminostilbene - 2 : 21 - disulphonic acids containing a group convertible to an amino group in 41 - position (e.g. nitro or acylamino), by diazotization and coupling with an azo component, converting the 41 - substituent to amino and again diazotizing and coupling, at least one of the azo components being an 8-oxyquinoline, (3) from a 4 - amino - 41 - aroylaminostilbene - 2:21-disulphonic acid by diazotizing and coupling with an 8 - oxyquinoline, (4) from a 4 - aminostilbene - 2 : 21 - disulphonic acid containing a group convertible to an amino group in 41 - position by reaction with phosgene or a cyanuric halide and conversion of the convertible groups to amino to give a symmetrically substituted urea or triazene compound, or mixed with a 4 - amino - 41 - oxy - 1 : 11 - azobenzene - 31 - carboxylic acid to give an asymmetrical body, followed by tetrazotization or diazotization respectively and coupling with an 8-oxyquinoline. The products dye or print wool, silk, leather, cotton, linen, artificial silk, or regenerated cellulose. They may be converted to copper, chromium, iron, nickel, or cobalt complexes in substance, in the dyebath, or on the fibre, e.g. by the processes of Specifications 455,274 and 619,969. In examples, 4-amino-41 - nitro - 1 : 11 - stilbene - 2 : 21 - disulphonic acid is (1) condensed with phosgene alone to give a symmetrical body, which is reduced with iron and acetic acid and the product tetrazotized and coupled with 8 - oxyquinoline; (2) condensed with cyanuric chloride and aniline, N - methylaniline, or 1 - amino - 4 - oxybenzene - 3 - carboxylic acid, followed by reduction with sodium hydrosulphide, tetrazotization, and coupling with 8 - oxyquinoline; (3) condensed with phosgene and the dyestuff from 4 - diazo - 1 - oxybenzene - 6 - sulpho-2 - carboxylic acid and 4 - amino - 3 - methoxy - 6 - methylbenzene, followed by reduction with sodium sulphide, diazotization, and coupling with 8 - oxyquinoline; (4) diazotized and coupled with salicylic acid or 1 - phenyl - 3 - methyl - 5 - pyrazolone, followed by reduction with sodium hydrosulphide, diazotization, and coupling with 8 - oxyquinoline. Also in examples, (5) 4 : 41 - diaminostilbene - 2 : 21 disulphonic acid is tetrazotized and coupled with 8 - oxyquinoline; (6) 41 - benzoyl-amino - 4 - amino - 1 : 11 - stilbene - 2 : 2 - disulphonic acid is diazotized and coupled with 8 - oxyquinoline.