Patent GB-299501-A (GB)
Title: New intermediates and dyes therefrom
Filed: 1927-07-27
Abstract: 299,501. British Dyestuffs Corporation, Ltd., and Mendoza, M. July 27, 1927. Nitro- and amino-diarylsulphides. - Aminodiarylsulphides of the type substituted in the 5-position, or carrying a benzo group in positions 5 : 6, in which Ar represents an aromatic residue carrying at least one amino group, are obtained by reduction of the products of condensation of the corresponding 1-thiol-2- oxy-3-carboxylic acid with an aromatic nitro compound carrying labile halogen. Specified thiol compounds are 3-thiol-5-methyl (or chloro) salicylicacid and 1-thiol-2 : 3-oxynaphthoic acid, and specified nitro compounds are 1 : 2- and 1 : 4- chloronitrobenzenes, 1 - chloro-2-nitrobenzene-4- sulphonic acid. 1 - chloro-4-nitrobenzene-2-sulphonic acid, and 1-chloro-2 : 4-dinitrobenzene, 1- chloro-2 : 4-dinitronaphthalene, 4 - chloro-3-nitrobenzaldehyde, 4-chloro-3-nitrobenzoic acid, 2- chloro-5-nitrobenzoic acid, 4-chloro-3-nitrobenzonitrile, and 2-chloro-5-nitrobenzonitrile. According to examples 3-thiol-5-methyl (or chloro) salicylic acid or 1-thiol-2 : 3-oxynaphthoic acid is condensed with 1-chloro-2-nitrobenzene-4-sulphonic acid, 1-chloro-4-nitrobenzene-2-sulphonic acid, or 2 : 4-dinitrochlorobenzene and the nitro- or dinitrodiarylsulphide is reduced, without isolation if desired, e.g. by iron and acid or by stannous chloride. 3-Thiol-5-methylsalicylic acid is obtained by treating 3-chlorosulphonyl-5-methylsalicylic acid or the corresponding sulphinic acid with zinc dust and reducing the resulting 5 : 5<1>-dimethyl-3 : 3<1>- dithiodisalicylic acid, e.g. by alkaline hydrosulphite. 3-Thiol-5-chlorosalicylic acid and 1-thiol-2: 3- oxynaphthoic acid are prepared in analogous manner from the corresponding chlorosulphonyl compounds or sulphinic acids. Azo dyes.-The above aminodiarylsulphides are used as components in the manufacture of azo dyes which, due to the separation of a chelate group from a chromophoric group by the sulphide bridge, have the property of remaining unchanged in shade on after-chroming. The monoaminosulphides may be diazotized and coupled with the usual components, and the diaminosulphides may be treated with nitrous acid to produce dyes of the Bismarck brown type, or may be used as second components, or may be monoacylated and used as first components, or in some cases may be tetrazotized and coupled with components. In examples the following dyestuffs are specified :-(1) 2-ammo-4-sulpho-2<1>-oxy-3<1>-carboxy-5- methyl (or chloro)- diphenyl sulphide or 2-amino- 4-sulphophenyl-2-oxy-3-carboxynaphthyl sulphide # #-naphthol, 2:8:6 acid (acid coupling), or 1-(2: 5-dicbloro-4-sulpho) phenyl-3-methyl- 5-pyrazolone, (2) 1 : 4-naphthylamine sulphonic acid, or benzidine (tetrazotized), or benzeneazo-1-naphthylamine-6 (7)-sulphonic acid # 2: 4 - diamino - 2<1> - oxc-3<1>-carboxy-5<1>-methyl-diphenyl sulphide; (3) the monacetyl derivative of 2:4-diamino-2<1>-oxy-3<1>-carboxy-5<1>-methyl-diphenyl sulphide # 2 : 8 : 6 acid (acid coupling), R-salt, or 1-(2 : 5-dichlor-4-sulpho) phenyl-3- methyl-5-pyrazolone; (4) 2-amino-4-sulpho-2<1>- oxy-3<1>-carboxy-5<1>methyl-(or chloro)-diphenyl sulphide or 2-amino-4-sulphopbenyl-2<1>-oxy-3<1>-carboxynaphthyl sulphide # 4-methoxy-mtoluidine # phenyl-2: 5:7-acid. Specifications 245,865, 256,775, 260,058, 262,243, 272,024 and 297,855 are referred to.