Patent GB-543567-A (GB)
Title: Manufacture of azo-dyestuffs
Filed: 1940-05-10
Abstract: 543,567. Dyes ; dyeing ; ; artificial filaments ; cellulose derivative compositions. SOC. OF CHEMICAL INDUSTRY IN BASLE. May 10, 1940, Nos. 8447 and 8448. Convention dates, May 11, 1939 and April 23, 1940. [Classes 2 (ii), 2 (iii) and 15 (ii)] Monoazo dyes readily soluble in organic solvents are produced in substance or on the material to be dyed by coupling a 1-aryl-3- methyl-5-pyrazolone in which the aryl group is of the benzene series with a diazotized amine of the general formula any further substituents in either of the benzene nuclei being non-ionogenic and other than nitro groups. Specified non-ionogenic substituents are methyl and O-alkyl groups and halogen atoms: Specified diazo components are aniline-2-, 3- and 4-#-hydroxyethylsulphonamides, aniline - 4 - chloro - 3 - # - hydroxyethylsulphonamide and aniline-2-methyl-5-#- hydroxyethylsulphonamide. Specified coupling components are the 1-pbenyl-, 1-(o- and pmethyl) phenyl-, 1-(o-, m- and p-chloro) phenyl- and 1-(o-methoxy) phenyl-derivatives of 3- methyl-5-pyrazolone.. The products obtained in substance are suitable for use as pigments, e.g. for colouring lacquers and masses from which cellulose acetate artificial silk is spun, and for dyeing cellulose acetate artificial silk. Example (1) relates to the production of the dyestuffs, aniline-3-#-hydroxyethylsulphon - amide or aniline-2-chloro-4-#-hydroxyethylsulphonamide # 1-(o-chloro) phenyl-3-methyl-5- pyrazolone, aniline-2-#-hydroxyethylsulphon - amide # 1-(o-methyl) phenyl-3-methyl-5-pyrazolone, and aniline-3-#-hydroxyethylsulphonamide # 1-phenyl-3-methyl-5-pyrazolone. Example (2) relates to the incorporation of the dyestuff, pasted with ethylene glycol monomethyl ether, in a nitrocellulose lacquer. Example (3) relates to the formation of a film from a solution made by stirring a solution of the dyestuff in ethylene glycol monomethyl ether into an acetone solution of acetylcellulose. Specification 12205/09, [Class 2 (iii)], is referred to. Aniline-#-hydroxyethylsulphonamides of the above general formula are obtained by reducing the nitro group in the products of reaction of the corresponding nitrobenzene sulphonic acid chlorides with ethanolamine. The Specification as open to inspection under Sect. 91 comprises also the production of azo dyestuffs by coupling a similar 1-aryl-3-methyl- 5-pyrazolone which may, however, be nitrosubstituted. with a similar diazotized amine of the general formula which may also however, be nitro-substituted, wherein R is any aliphatic residue containing 2 carbon atoms of which the α-carbon atom carries 2 hydrogen atoms and the #-carbon atom carries a hydroxyl group. Additional diazo components specified are aniline-2-, 3- or 4-#-hydroxyethylsulphone, aniline-2-chloro- or nitro-4-#-hydroxyethylsulphone, aniline - 4 - chloro-2-#-hydroxyethylsulphone, aniline-2-, 3- or 4 - sulphonic acid - # - hydroxyethyl ester, aniline - 2 - chloro - 4 - sulphonic acid - # - hydroxyethyl ester and aniline-3-N-methyl- or ethyl-N-#-hydroxyethylsulphonamide, and additional examples of the production of dyestuffs from various combinations of the components are given. Aniline-#-hydroxyethsulphones of the above general formula are obtained by reducing the nitro group (a) in the product of reaction with a #-halogenethanol of the sulphinic acid obtained by reduction of the corresponding nitrobenzenesulphonic acid chloride, (b) in the product, obtained by oxidizing the thioether obtained by reaction of #-chloroethanol with a nitrothiophenol obtainable by replacement of the halogen in a nitrohalogenbenzene by the thiol group. Aniline sulphonic acid-#-hydroxyethyl esters of the above general formula are obtained by reducing the nitro group in the product of reaction of the corresponding nitrobenzenesulphonic acid chloride with ethylene glycol. This subject-matter does not appear in the Specification as accepted.