Patent GB-260058-A (GB)
Title: Manufacture of new intermediates and dyestuffs
Filed: 1925-07-31
Abstract: 260,058. British Dyestuffs Corporation, Ltd., Saunders, K. H., and Mendoza, M. July 31, 1925. Nitro- and amino-diaryl sulphides.-Mono- and poly-nitro derivatives of 4-oxydiphenylsulphide- 3-carboxylic acid, its homologues or substitution products, are obtained by condensing 5-thiolsalicylic acid, its sodium salt, or homologues or substitution products with aromatic nitro-compounds containing a labile nuclear halogen atom. The corresponding amino compounds are obtained on reduction, e.g. with iron and hydrochloric acid. In examples, 5-thiolsalicyclic acid and its 3-chlor derivative are condensed with 2 : 4-dinitrochlorbenzene and 5-thiolsalicylic acid and its 3-methyl derivative are condensed with 4-chlor-3-nitrobenzene sulphonate of sodium. 4-Chlor-3-nitrobenzoic acid and 2: 6-dinitrochlorbenzene-4-sulphonic acid may also be condensed with 5-thiolsalicylic acid. 5-Thiolsalicylic acid maybe obtained by treating 5 :5<1>-dithiosalicylic acid with reducing agents, e.g. sodium hydrosulphite. 3-Methyl-5-thiolsalicylic acid (5-thiol-2-oxy-mtoluic acid) is obtained by reducing 5-chlor-sulphonyl-2-oxy-m-toluic acid to the corresponding sulphinic acid. On further reduction, this yields a mixture of 3 : 3<1>-dimethyl-4 : 4<1>-dioxy-5 : 5<1>- dicarboxy-diphenyl-sulphide and 3-methyl-5- thiolsalicylic acid, from which the thiol may be extracted with boiling water. 3-Chlor-5-thiolsalicylic acid is obtained from 3- chlorsalicylic acid by treating with chlorsulphonic acid, reducing the 3-chlor-5-chlorsulphonylsalicylic acid obtained to the corresponding sulphinic acid, and further reducing the latter to 3 : 3<1>-dichlor-4 : 4<1>-dioxy-5 : 5<1>-dicarboxy-diphenyldisulphide, which yields the thiol on treating with sodium hydrosulphite in cold alkaline solution. Azo dyes. - The above amino diarylsulphides are used as components in the manufacture of azo dyes. The monoamino sulphides may be diazotized and coupled with the usual components. and the diaminosulphides may be used as second components, or they may be partly acylated and used as first components. Disazo and polyazo dyestuffs may be obtained by coupling the diaminosulphides with a tetrazotized diamine; by coupling the diazotized monamino sulphides with amines, such as p-xylidine, cresidine, a-naphthylamine, or its methyl-#-sulphonate, rediazotizing and again coupling; or by coupling the diazotized monaminosulphides with components capable of coupling a second time under different conditions with a second diazo compound; or by diazotizing a nitramine, coupling it to a diaminosulphide, reducing the nitro-group, rediazotizing and coupling to other components. In examples (1) 2<1> - amino-4<1>-sulpho-4-oxydiphenylsulphide-3-carboxylic acid is diazotized and coupled with #- naphthol; acetyl-H-acid, 2<1> : 5<1>-dichlor-4<1>-sulphophenyl-3-methyl-5-pyrazolone gamma-acid, or Schaeffer acid may also be used; (2) p-nitraniline-osulphonic acid, naphthionic acid, or 2 : 5-dichloraniline are diazotized and coupled with 2<1> : 4<1>- diamino-4-oxydiphenylsulphide-3-carboxylic acid; (3) the monoazo dyestuff from p-nitraniline-osulphonic acid and the diaminosulphide is reduced by sodium sulphide, rediazotized and coupled with a second molecule of the diaminosulphide, or with acetyl-H-acid; (4) benzidine-m-disulphonic acid is tetrazotized and coupled with two molecules of the diaminosulphide; (5) the diaminosulphide is monoacetylated, diazotized, and coupled with a component, e.g. 2-methylaminonaphthalene-7-sulphonic acid, 2 : 8-aminonaphthol-6-sulphonic acid, or 2<1> : 5<1>-dichlor-4<1>-sulphophenyl-3-methyl-5-pyrazolone; and (6) 2<1>- amino-4<1>-sulpho-5-methyl-4-oxydiphenylsulphide-3- carboxylic acid is diazotized and coupled with a component, e.g. 2<1>:5<1>-dichlor-4<1>-sulphophenyl-3- methyl-5-pyrazolone, #-naphthol or 2 : 8-aminonaphthol. The diamine obtained by condensing 3-chlor-5-thiolsalicylic acid with 2 : 4-dinitrochlorbenzene may also be used as a coupling component, or its monoacetyl derivative may be diazotized and coupled with the usual components. The products dye cotton and wool in various shades which are little changed by subsequent chroming.