Patent GB-540743-A (GB)
Title: Manufacture of azo-dyestuffs and intermediate products
IPC: C07D307/91
Filed: 1940-04-26
Abstract: 540,743. Dyes ; diphenylene oxide derivatives. SOC. OF CHEMICAL INDUSTRY IN BASLE. April 26, 1940, Nos. 7539 and 7540. Convention dates, April 27, 1939, and April 6, 1940. [Classes 2 (iii) and 15 (ii)] Amides, suitable for use in the manufacture of azo dyes by coupling with diazo compounds in substance or on the fibre, are obtained by condensing a #-ketocarboxylic acid ester, capable of enolisation, with an amine of the general formula wherein X represents alkoxy and Y represents H, halogen, methyl, alkoxy or acidylamino (c.f. Specifications 374,548 and 472,823). Specified amines of this formula are the 3-methoxy-, 3- ethoxy-, 3:6- and 3:7-dimethoxy-, 3-methoxy-7- chloro-, 3-ethoxy-7-methyl- and 3:6-dimethoxy-7- acetylamino derivatives of 2-aminodiphenylene oxide. The dyestuffs containing sulphonic or carboxylic acid groups are suitable for dyeing wool or cotton and those obtained from ohydroxy- or o-carboxy-diazo compounds are convertible into complex metal compounds. The dyestuffs containing no sulphonic or carboxylic acid groups are suitable for use as pigments or for formation on textile materials, especially natural or regenerated cellulose materials. Specified diazo components for this purpose are aniline and its homologues, 2- and 3-chloroanilines, 2-methyl-3- or 4-chloroaniline, 2:5- dichloroaniline, 4- or 5-nitro-2-methoxyaniline, the 4-chloro- and 4:4<SP>1</SP>-dichloro-derivatives of 2-aminodiphenyl ether, 2-methyl-4-nitroaniline, 2-nitroaniline, 4-chloro-2-nitroaniline, 2-nitro-4- methoxyaniline, the p-chlorophenyl ester of anthranilic acid (c.f. Specification 478,609), 1- and 2-naphthylamines, 2:5-diaminohydroquinone dimethyl or diethyl ethers monoacylated with benzoyl chloride or an aryloxyacetic acid chloride, 4-aminoazobenzene and its 3:21-dimethyl-, 5-methoxy-, 2:5-dimethoxy- and 2-methyl-5-methoxy derivatives. In examples, (1) ethyl acetoacetate is condensed with 2- amino-3-methoxy- or ethoxy-diphenylene oxide by heating for 4-5 hours under reflux in chlorobenzene containing a few drops of diethylaniline ; (2) and (3) ethyl acetoacetate is similarly condensed with the 3:6-dimethoxy- and the 3:6-dimethoxy-7-acetylamino-derivatives; (4) ethyl benzoylacetate is condensed with 2-amino-3-ethoxydiphenylene oxide by heating for 3 hours in chlorobenzene under reflux; (5) diazotized dehydrothiotoluidine is coupled in substance with 2-acetoacetylamino-3-methoxydiphenylene oxide ; the product dyes cotton and viscose artificial silk yellow ; (6) cotton yarn is impregnated with 2-aceto-acetylamino-3- methoxy- or ethoxy-diphenylene oxide, which is then developed with diazotized 2-methyl-4- nitroaniline, 2-nitroaniline, 4-nitro-2-methoxyaniline, 3-chloroaniline, 2:5-dichloroaniline or 4-chloro-2-aminodiphenyl ether; (7) cotton yarn is impregnated with 2-benzoylacetylamino- 3-ethoxydiphenylene oxide, which is then developed with diazotized 2-methyl-3-chloroaniline, 2- or 3-chloroaniline or 4-chloro-2- aminodiphenyl ether ; (8) cotton yarn is impregnated with 2-acetoacetylamino-3:6-dimethoxy - 7 - acetylaminodiphenylene oxide, which is then developed with diazotized 2- or 3-chloroaniline, 2:5-dichloroaniline or the pchlorophenyl ester of anthranilic acid. 2- Amino-3:6-dimethoxydiphenylene oxide is obtained by reacting diazotized 2-chloro-4- acetylamino-5-methoxyaniline with benzoquinone, reducing the product with zinc dust in acetic acid, treating the reduced product with caustic potash at 150‹C. to form the diphenylene oxide ring with simultaneous saponification of the acetylamino group, re-acetylating the amino group, methylating the 6-hydroxy group with dimethyl sulphate and finally saponifying the acetylamino group. 2- Amino-3:6-dimethoxy-7-acetylaminodiphenylene oxide is obtained by nitrating the 3:6- dimethoxy-2- (or 7-) acetylaminodiphenylene oxide obtained as above prior to the final saponification and reducing the nitro group. The Specification as open to inspection under Sect. 91 comprises also (a) the manufacture of the corresponding amides in which X represents H, including specifically those derived from 2-aminodiphenylene oxide, its 7-methyl, 7- methoxy-, 6- and 7-chloro-, 7-acetylamino- and 6-ethoxy derivatives and (b) an example of the production in substance of an azo dyestuff by coupling diazotized 4-nitro-2-methoxyaniline with 2-acetoacetylamino-diphenylene oxide. This subject-matter does not appear in the Specification as accepted.