Patent GB-391626-A (GB)
Title: Manufacture of primary disazo-dyestuffs
IPC: C09B33/10
Filed: 1932-06-02
Abstract: Azo dyes.--Primary disazo dyes are obtained by coupling 1 mol of a 1 : 8-aminonaphthol-sulphonic acid in an acid medium with 1 mol. of a diazotized aminoarylsulphonamide, other than an o-oxyaminoarylsulphonamide and thereafter coupling the monoazo product in an alkaline medium with 1 mol. of any diazo component. The sulphonamide group may be substituted by one or two hydrocarbon residues or substituted hydrocarbon residues.  The products dye wool and silk reddish blue to greenish blue and blue-black shades and are well absorbed even from a neutral Glauber salt bath.  The production of the following dyestuffs is described in examples: (1) 1-chloro-2-aminobenzene-4-sulphanilide --> (acid) 1 : 8-aminonaphthol-3 : 6-disulphonic acid (alkaline) \sM 1-methyl-4-aminobenzene-2-sulphanilide; (2) 1-chloro - 2 - aminobenzene - 4 - sulphanilide --> (acid) 1 : 8-aminonaphthol-3 : 6-disulphonic acid (alkaline) \sM 4-aminophenol-p-toluene-sulphonic ester; (3) 1-chloro-4-aminobenzene-2-sulpho-N-ethylanilide --> (acid) 1 : 8-aminonaphthol-3 : 6-disulphonic acid (alkaline) \sM 2-amino - 2<1> - methyldiphenyl ether.  A table is also given showing the shades obtainable on wool from an acid bath containing dyestuffs produced according to the invention from various components, the following components being specified in addition to those above referred to: (a) as aminoarylsulphonamides diazotized and coupled in acid medium, 1-chloro-2-aminobenzene-4-sulphamide, 1 - chloro - 2 - aminobenzene - 4 - sulphodimethylamide, 1 - methyl 4-amino-benzene 2-sulphanilide, aniline-3-sulphanilide, 1-chloro - 2 - aminobenzene - 4 - sulpho - 2<1> - anisidide, 1 - chloro - 2 - aminobenzene - 4 - sulpho-monobenzylamide, 1-chloro-2- aminobenzene - 4 - sulpho - 4<1> - toluidide, 1 - chloro - 2 - aminobenzene - 4 - sulpho-N-ethylanilide, 1 - chloro - 4 - aminobenzene - 2-sulphanilide, 1-methoxy - 2 - aminobenzene - 4-sulphanilide, 2-amino-4<1>-methyldiphenylsulphone - 4 - sulpho - N - ethylanilide, 1-chloro-2-aminobenzene - 4 - sulphanilide - 3<1> - sulphonic acid; (b) as components diazotized and coupled in alkaline medium, 4-chloro-2-aminodiphenyl ether, 2-chloraniline, 4-aminodiphenyl ether, 1- or 2-naphthylamine, 2-aminodiphenyl ether - 4 - sulphonic acid; (c) as 1 : 8-aminonaphtholsulphonic acids, 1 : 8-aminonaphthol - 4 - sulphonic acid and 1 : 8-aminonaphthol-4 : 6-disulphonic acid. Specifications 15725/91, 9894/93, 15269/93, 12529/95, [all in p Class 2, Acids and salts, Organic &c.], and 12205/09, [Class 2 (iii), Dyes &c.], are referred to.  1 - Chloro - 1 - aminobenzene - 4 - sulphamide and the corresponding sulphanilide, sulphodimethylamide, sulpho-2<1>-anisidide, sulpho-4<1>-toluidide, sulpho-N-ethylanilide and sulphanilide-3<1>-sulphonic acid are obtained by reduction of the products of condensation of 2-nitro-1-chlorobenzene-4-sulphochloride with ammonia, aniline, dimethylamine, 2<1>-anisidine, 4<1>-toluidine, monoethylaniline and metanilic acid respectively.  1 - Chloro - 2 - aminobenzene - sulphomonobenzylamide is obtained by condensation of 2 - nitro - 1 - chlorobenzene - 4 - sulphochloride with ammonia followed by condensation of the product with benzyl chloride and reduction of the nitro group.  1 - Chloro - 4 - aminobenzene - 2 - sulpho - N - ethylanilide is obtained by reduction of 1-chloro-4-nitrobenzene-2-sulpho-N-ethylanilide.  1 - Chloro - 4 - aminobenzene - 2 - sulphanilide is obtained by reduction of the condensation product of 4-nitro-1-chlorobenzene-2-sulphochloride with aniline.  2 - Amino - 4<1> - methyldiphenylsulphone - 4 - sulpho - N - ethylanilide is obtained by reduction of the condensation product of 1-chloro-2-nitrobenzene-4-sulpho-N-ethylanilide, obtainable as above, with p-toluenesulphinic acid.