Patent GB-265641-A (GB)
Abstract: 265,641. Ransford, A. J., (Cassella & & Co., Ges., L.). Aug. 7, 1925. 4-Arylamino-1-amino-2-thiophenols; azo, sulphuretted, and thioindigoid dyes. - The arylamino-arylene-2 : 1-thiazthionium compounds obtained by condensing aromatic amines with such of the products of the action of disulphurdichloride on aromatic amines as contain a labile substituent in the p-position to the nitrogen atom, and having the formula (Ar and R=aryl residues, X=hydrogen, alkyl, or aralkyl) are treated with alkalies with or without a reducing agent. The products are probably 4- arylamino-1-amino-2-thiophenols and yield with alkyl or aralkyl alides thioethers which can be used in the manufacture of azo dyestuffs in substance or on the fibre; they also condense with chloracetic acid to give o-aminoarylthioglycollic acids which can also yield azo dyes or thioindigoid dyes. By condensation with arylquinones or cheir substitution derivatives, particularly halogen derivatives, the o-aminoarylmercaptans yield vat dyestuffs which are probably thiazines and dye wool from the vat in fast violet to blue or black shades; these quinone dyestuffs, by treatment with sulphurizing-agents, yield products which dye vegetable fibres in blue to black shades from the vat or sulphide bath. According to examples (1) 6-methyl-4-chlor-2 : 1-phenylene-thiazthionium chloride (from o-toluidine and disulphur dichloride as described in Specification 17417/14) is condensed with aniline and the product treated with caustic soda and sodium hydrosulphite; the resulting 6-methyl-4-phenylamino-1-amino-2-thiophenol is isolated as the zinc or lead salt; the alkali salts can also be obtained by salting out and yield the hydrochloride with hydrochloric acid : (2) the compound is similarly obtained from the condensation product of benzidine and 6-methyl-4-chlor--2 : 1- phenylene-thiazthionium chloride; (3) 6-methyl- 4-phenylamino-1 : 2-aminothiophenol is condensed with chloranil or di- or tri-chlorquinone, or quincne itself, the products dyeing wool from the vat in violet-blue shades; 1-amino-4-phenylamino-2- thionaphthol (made by reducing the product from aniline and 4-chlor-2 : 1-naphthylene-thiazthionium chloride) condensed with #-oxy-a-naphthoquinone or 2 : 3-dichlor-a-naphthoquinone yields grey-blue to black vat dyes; the o-aminomercaptans may be replaced by the corresponding oamino-thiosulphonic acids or the o-o<1>-diaminodiaryldisulphides; the dyestuffs may also be obtained by treating an alkaline solution of the mercaptan or thiosulphonic acid and a hydroquinone of the benzene or naphthalene series with air in the presence of a catalyser; (4) the zinc salt of 6-methoxy-4-phenylamino-1 : 2 - aminothiophenol is condensed with chloranil or 2 : 5- or 2 : 6-dichlorquinone; (5) acid dyes are obtained by condensing chloranil or mono-, di-, or tri-chlorquinone, or toluquinone with 1-amino-2-mercapto-6- methyl-4-diphenylamino-2<1>-or 3<1>-carboxylic acid (obtained by condensing 4-chlor-6-methyl-2 : 1- phenylenethiazthionium chloride with o- or maminobenzoic acid and reducing the product); (5) the condensation product from 6-methyl-4-phenylamino-1 : 2-aminothiophenol and chloranil is heated with alcohol, sodium sulphide, and sulphur ; the product dyes cotton in fast blue shades from the vat or sodium sulphide bath. o-Aminothiosulphonic acids and o-aminodisulphides corresponding with the above 4-arylamino- 1-amino-2-thiophenols are obtained by oxidizing the alkaline solutions of the latter to obtain the disulphides, which are then treated with sulphurous acid as in Specification 4792/00, [Class 2, Acids and salts, Organic &c.], to obtain the thiosulphonic acids.