Patent GB-512579-A (GB)
Title: Manufacture of azo-dyestuffs
IPC: C09B29/08
Filed: 1938-03-15
Abstract: 512,579. Dyes and intermediates ; dyeing and printing. SOC. OF CHEMICAL INDUSTRY IN BASLE. March 15, 1938, Nos. 8003 and 8004. Convention dates, March 15, 1937, and Feb. 22, 1938. [Classes 2 (iii) and 15 (ii)] Azo dyes ; acid wool dyes without mordants, dyeing with; cellulose esters, dyeing ; printing.- Azo dyestuffs are manufactured by coupling a diazo compound of an aromatic amine, having a nitro group in p-position to the diazotizable amino group, with a coupling component of the general formula in which X is a methyl, alkoxy or acidylamino group and Y is hydrogen, halogen or an acidylamino group, and in which other substituents may be present. The products are suitable for dyeing or printing animal materials, e.g. wool, leather and silk, or acetate artificial silk. Examples describe the production of the following dyestuffs : (1) 1-amino-4-nitrobenzene-2- methylsulphone# 2-methoxy-5-methyl-4<1>-acetylaminodiphenplamine-2<1>-sulphonic acid; the product dyes wool from an acid bath bluish violet shades ; the diazo component may be - replaced by 1-amino-2:4-dinitro-6-chloro- or 6-bromobenzene, 1-amino - 4 nitro - 2 - cyanobenzene or 1-amino-4-nitro-2-cyano-6-chloro- or - 6 bromobenzene; (2) 1-amino-4-nitrobenzene- 2-methylsulphone# 2-ethoxy - 5 - methyl-4<1>- acetylaminodiphenylamine-2<1>-sulphonic acid (reddish blue shades); (3) 1-amino-4-nitrobenzene - 2 - methylsulphone# 2 - ethoxy - 5 - methyl-4<1>-chloracetylaminodiphenylamine - 21 - sulphonic acid (violet blue shades) or 2-ethoxy- 5-methyl-4<1>-chloracetylamino-6<1>-chlorodiphenylamine-2<1>-sulphonic acid (violet shades) (4) 1-amino-4-nitrobenzene-2-methylsulphone #2- ethoxy- 5 - methyldiphenylamine - 2<1>- sulphonic acid (violet shades) ; the diazo component may be replaced by 4-nitroaniline, 4-nitro-2-chloraniline or 4-nitro-2-methoxy-1-aminobenzene (5) 1-amino-4-nitrobenzene-2-methylsulphone# 2 - ethoxy-5-methyl-4<1>-o-chlorobenzoylaminodiphenylamine-2<1>-sulphonic acid (blue shades); the diazo component may be replaced by 1- amino-4-nitrobenzone-2-sulphonic and dimethylamide or phenylethylamide; (6) 2:6- dichloro-4-nitroaniline# 2-ethoxy-5-methyl-4<1>- chloracetylaminodiphenylamine - 2<1> - sulphonic acid (red-brown shades); (7) 2:6-dichloro-4- nitraniline# 2-ethoxy-5-methyldiphenylamine- 21-sulphonic acid; the product dyes wool redbrown shades and may also be used for dyeing and printing acetate artificial silk; the diazo component may be replaced by 2-cyano-6- chloro-4-nitraniline ; (8) acetate artificial silk yarn is dyed with the product of (7) from a bath containing sodium sulphate ; (9) wool is dyed with the product of (4) from a bath containing sodium sulphate and sulphuric acid. Other components specified are : diazo components : 4-nitraniline-2-sulphonic acid, 1-amino-4-nitrobenzene-2-ethyl- and-benzylsulphones and. 1- amino-4-nitro-6-chlorobehzene- 2 - methylsulphone ; coupling components : 3-methyldiphenylamine-21-sulphonic acid and its 4<1>-acetylamino-; 4<1>-chloro- and 4<1>-chloracetylamino-derivatives, 3-methoxy -4<1> - acetylaminodiphenylamine- 21- sulphonic acid, 3-methyl-5-methoxydiphenylamine-2<1>-sulphonic acid and its 4<1>-acetylamino-, 41-chloracetylamino-, 4<1>-benzoylamino-, 4<1>-ochlorobenzoylamino- and 41-chloroderivatives, the corresponding compounds containing ethoxy instead of methoxy groups, 2:5-dimethoxydiphenylamine-2<1>-sulphonic acid, 2:5-dimethoxy- and -diethoxy - 4<1> - chloracetylaminodiphenylamine-21-sulphonic acid, 3-acetylamino-5-methoxy- or -ethoxy-4<1>-acetylamino- or -chloracetylaminodiphenylamine-2<1>-sulphonic - acid, 3- methyl-5-methoxy-4<1>-acetylamino-6<1>- chlorodi - phenylamine-2<1>-sulphonic acid and 3-methyl-5- methoxy-4-ehloracetylamino-6<1>-chlorodiphenylamine-21-sulphonic acid. Specifications 220,303, [Class 2 (iii)], 447,561 and 451,970 are referred ' to. Diphenylaminesulphonic acids of the general formula given above are obtainable by condensing an aromatic amine, containing in m position to the amino group a methyl, methoxy, ethoxy or acidylamino group, with 4-nitro-1- chlorobenzene-2-sulphonic acid, reducing the nitro group, and acylating the amino group or diazotizing it and replacing.the diazo group by hydrogen or a halogen atom. The condensing is preferably effected by using the 4-nitro-1- chlorobenzene-2-sulphonic acid in the form of its alkali metal salt and working with excess of the amine or with the addition of another acidbinding agent,e.g. sodium carbonate, magnesium oxide or calcium carbonate. In examples : (1) the sodium salt of 1-chloro-4-nitrobenzene-2- sulphonic acid is heated with 2 molecular proportions of 1-amino-2-methoxy-5-methylbenzene and the product is reduced with iron in aqueous acid solution and treated with acetic anhydride ; (4) 2-ethoxy-5-methyl-4<1>-aminodiphenylamine-21-sulphonic acid is diazotized and the diazo group is removed by stirring with alcohol in the presence of copper. Other amines specified as starting materials are : m-toluidine, m-anisidine, 2-ethoxy-5-methylaniline, 2:5-dimethoxy- and -diethoxyaniline, 3-acetylaminoaniline, 3-chloracetylaminoaniline and 2-methoxy- and -ethoxy-5-acetylaminoaniline.