Patent GB-517918-A (GB)
Title: Manufacture of azo-dyestuffs
IPC: C09B29/08
Filed: 1938-07-11
Abstract: 517,918. Dyes; intermediates. SOC. OF CHEMICAL INDUSTRY IN BASLE. July 11, 1938, Nos. 20492, 20493 and 20494. Convention dates,Sept. 18, 1937, Jan. 6, 1938 and April 27, 1938. [A Specification was laid open to inspection under Sect. 91 of the Acts, Jan. 11, 1939.] [Classes 2 (iii) and 15 (ii)] Azo dyes free from sulphonic groups are made by coupling a diazo compound of an aromatic amine which contains a nitro group in pposition to the amino group with a coupling component of the general formula where X is hydrogen or alkyl, and Z is a bridge of at least 2 carbon atoms, and the benzene ring may be substituted, e.g., by methyl or alkoxy groups, provided that the p-position to the substituted amino group is free to couple. 'The same dyes may be made by reacting the dyestuffs from diazotized p-nitraniline and hydroxyalkylaminobenzenes with polycarboxylic acids in which two carboxylic groups are linked by a bridge of at least 2 carbon atoms, or reactive derivatives of such acids. The products, particularly in the form of their alkali metal and ammonium salts, are water-soluble, and dye wool, cotton and cellulose esters and ethers in orange, brown, red; blue and green tints. If the dyestuff contains a free amino group it may be diazotized on the fibre and developed with a coupling component. Specified polycarboxylic acids for making the intermediate coupling components or reacting with the azo dyes are succinic, glutanic, adipic pimelic, fumanic, maleic, phthalic and naphthalic acids, which may be substituted in the aliphatic chain or in the aromatic nucleus by alkyl, hydroxyl or amino groups. Such acids, or'their anhydrides, halides, or esters may be reacted with the following bases, to produce intermediate coupling components : N-methyl-, ethyl-, propyl-, isopropyl-, butyl-, isobutyl-, amyl- or cetyl-N-oxyethylanilines, N-substitu- - tion products of m-toluidine or 5-methyl-2- methoxyaniline, e.g., N-propyl- or butyl-N- oxyethyl-3-methylaniline, also N-substitution products of 3-acidylaminoaniline, e.g., 3- acetylamino-6-methoxy N-ethyl-N-oxyethylaniline. As diazo components, the following are specified : p-nitraniline, 4-nitro-2-chlor-, methoxy-anilino, or -cyano, 2:6-dinitraniline, 2:4-dinitro-6-cyano-aniline, 2:4-dinitrohalogenaniline, 4-nitro- and 4:6-dinitro-aniline-2- methylsulphone, and 4-nitro-6-chloraniline-2- methylsulphone. In examples, (1) p-nitroaniline is diazotized and coupled with the product obtained by condensing N-ethyl-N-oxyethylaniline with phthalic anhydride, the product dyes acetate artificial silk in red tints ; the same product is obtained by reacting the azo dye p-nitraniline #N-ethyl-N-oxyethylaniline with phthalic anhydride, (2) 4-nitraniline-2- methylsulphone is diazotized and coupled with the condensation product from N-ethyl-noxyethyl-m-toluidine and maleic anhydride, the product dyes acetate artificial silk in violet tints, (3) 4-nitro-2-chloraniline is diazotized and coupled with the monomaleic ester of N- methyl or ethyl-N-oxyethyl-3-methyl-6-methoxyaniline, and (4) 3-methyl-6-methoxyaniline is converted into the N-butyl derivative by reaction with p-toluene sulphonic acid butyl ester, the product is treated with ethylene chlorhydrin to introduce an oxyethyl group, and the N-butyl-N-oxyethyl-3,-methyl-6-methoxyaniline is reacted with maleic anhydride and the product coupled with diazotized pnitraniline 4-nitranaline-2-methylsulphone, or 4:6-dinitraniline-2-methylsulphone ; dyestuffs dyeing acetate artificial silk in red, violet and blue shades are obtained. The shades produced on acetate artificial silk with the dyestuffs obtained by using various monophthalic, monosuccinic and monomaleic esters ane tabulated. Specifications 422,843 and 447,561 are referred to. The Specification as open to inspection under Sect. 91 is not restricted to unsulphonated dyestuffs, and mentions 4-nitraniline-2-sulphonic acid as a diazo component. Oxalic and malonic acids are also specified as acids from which the esters may be made. This subject-matter does not appear in the Specification as accepted.