Patent GB-376961-A (GB)
Title: Manufacture of nitro-aminodiphenyl sulphides
Filed: 1931-07-25
Abstract: Nitroaminodiphenylsulphides are prepared by reacting a 1 : 2- or a 1 : 4-chlornitrobenzene or a substitution product thereof with a soluble sulphide to produce an aminothiophenol and reacting this aminothiophenol with 1 : 2- or a 1 : 4-chlornitrobenzene or a substitution product thereof.  In most cases the chlornitrobenzene used in the second phase may be added directly to the liquid containing the first phase.  In examples: (1) A solution of sodium sulphide and p-chlornitrobenzene is heated and after cooling zinc sulphate solution is added, the precipitate is dissolved in dilute aqueous hydrochloric acid, and the zinc compound of 4-aminothiophenol obtained by adding zinc sulphate and salt; a mixture of this compound and p-chloronitrobenzene is dissolved in dilute caustic soda, the solution boiled and excess of p-chloronitrobenzene steam-distilled off, giving crystalline 4 - nitro - 4<1> - aminodiphenylsulphide. (2) 1-Chloro-4-nitrobenzene (or 1-chloro-2-nitrobenzene, 1 : 4-dichloro-2-nitrobenzene, 1-chloro4-nitro-2-benzene sulphonic acid) is added to a solution of sodium sulphide in water and after the whole has been boiled and steamblown 1-chloro-4-nitrobenzene (or 1-chloro-2-nitrobenzene, 1 : 4-dichloro-2-nitrobenzene, 1 - chloro - 4 - nitro - 2 - benzene sulphonic acid, 1 - chloro - 4 - nitro - 2 - benzene carboxylic acid, 1-chloro-2 : 4-dintrobenzene) is added and the whole boiled; excess of the chloronitrobenzene is removed by a current of steam and the crystalline product is filtered off.  (3) A solution of 1-chloro-2 : 4-dinitrobenzene in alcohol is added to the cooled product obtained by treating p-chloronitrobenzene with sodium sulphide to obtain 4-amino-2<1> : 4<1>-dinitrodiphenylsulphide.  (4) The sodium salt of 1 - chloro-4-nitro-2-benzenesulphonic acid is added to the intermediate product obtained by treating o-chloronitrobenzene with sodium sulphide from which any chloraniline formed has been removed by steam and after boiling the product is salted out giving the sodium salt of 4<1> - nitro - 2 - aminodiphenylsulphide - 2<1> - sulphonic acid; the product is purified by dissolving in water, filtering and precipitating by means of hydrochloric acid.  (5) p-Chloronitrobenzene is added to the intermediate product obtained by treating sodium p-nitrochlorobenzene-o-sulphonate with sodium sulphide, the excess of p-chloronitrobenzene being removed by steam; the sodium 4-nitro-4<1>-aminodiphenylsulphide - 2<1> - sulphonate separates from the mother liquor on cooling.  (6) p-Chloronitrobenzene is boiled with an aqueous solution of sodium sulphide and sulphur and after filtering a solution of chloronitrobenzene in caustic soda solution is added; unchanged chloronitrobenzene is removed by steam and a product consisting of 4-nitro-4<1>-aminodiphylsulphide is obtained. The sulphur used may be replaced by sodium hydrosulphide.  A table is given showing the properties of the products obtained by using 1-chloro-4 (or 2-)-nitrobenzene in the first phase and 1-chloro-4(or-2-)-nitrobenzene, 1 - chloro - 2 - nitrobenzene-2-sulphonic acid, 1-chloro-4-nitrobenzene-2-sulphonic acid or 1-chloro-4-nitro2-benzoic acid in the second phase; 1-chloro-4-nitrobenzene in the first phase and 1-chloro-2 : 4-dinitrobenzene or 1-4-dichloro-2-nitrobenzene in the second; 1-chloro-4-nitro-2-benzenesulphonic acid in the first and 1-chloro-4-nitrobenzene in the second and 1 : 4-dichloro-2-nitrobenzene in the first and second phases.  Azo dyes.--The nitroaminodiphenylsulphides described above give red, orange, and yellow insoluble azo dyes by diazotizing and coupling with b -naphthol.