Patent GB-716753-A (GB)
Title: Manufacture of cobaltiferous azo-dyestuffs
Filed: 1952-08-13
Abstract: A number of acylacetic amides and esters of the formula R-CO-CH2-CO-Y-R1, where Y is -O-, -NH- or -N(alkyl)-, are stated to be obtainable by known methods, e.g. reaction of diketene with hydroxy or amino compounds, followed if desired (1) if an ester, by heating with an amine to give an amide, or (2) if R is to be other than methyl, by condensation with an acyl halide and removal of the original acetyl group by hydrolysis.  In the products specified R is methyl, phenyl, p-tolyl, p-chlorophenyl, p-methoxyphenyl and naphthyl, and R1 is methyl, ethyl, hydroxyethyl, isopropyl, butyl, phenyl, tolyl, xylyl, ethylphenyl, chlorophenyl, dichlorophenyl, fluorophenyl, trifluoromethylphenyl, trifluoromethyl - chlorophenyl, methoxyphenyl, dimethoxy - chlorophenyl, sulphonamidophenyl, N - methylsulphonamidophenyl, sulphonamido-chlorophenyl and sulphonamido-tolyl.ALSO:The invention comprises cobaltiferous azo dyes containing monoazo dyestuffs bound in complex union, the ratio of metal atoms to dyestuff molecules being less than 1 : 1 (and preferably about 1 : 2); the monoazo dyestuffs, which may be the same or different, are free from sulphonic acid and carboxylic acid groups and at least one is of the formula: <FORM:0716753/IV(c)/1> where R is a benzene residue containing an o-hydroxy group, Y is -O-, -NH- or -N(alkyl)-, R1 is an aliphatic, alicyclic or aromatic residue and Z is an aromatically bound sulphonamide group, with the proviso that if Z is -SO2 NH2 Y is -N (alkyl)- or the dyestuff contains a further aromatically bound substituted sulphonamide group or an aromatically bound nitrogen-free non-solubilizing substituent; the other dyestuff, if not also of the above formula is an o : o1-dioxy-azo compound, preferably a benzene-azo-pyrazolone or p  benzene-azo-naphthalene. The cobaltiferous dyestuffs are made by normal methods of metallising a monoazo or mixture of two monoazo dyestuffs.  Preferably there is used less than 1 atom of cobalt per dyestuff molecule and/or the process is carried out in weakly acid or alkaline medium.  Suitable metallising agents are simple cobalt compounds such as the hydroxide, sulphate and acetate and complex cobalt compounds of aliphatic dicarboxylic and hydroxy-acids, e.g. oxalic lactic, glycollic, citric or tartaric. There may be present bases, salts of organic acids or organic solvents.  The metal-free starting materials may be obtained by coupling the appropriate diazotized o-aminophenol with the acylacetic ester or substituted amide.  The products of the invention can be used for dyeing and printing silk, leather, wool and superpolyamides or superpolyurethanes, from weakly alkaline to weakly acid baths.  In the examples (1) the dyestuff 2-aminophenol-4-sulphomethylamide --> acetoacetic o-chloroanilide is converted into its cobalt complex, (2) a mixed cobalt complex is obtained from the dyestuff of (1) and 2-aminophenol-4-sulphomethylamide-->1-(p-chlorophenyl) -3-methyl-5-pyrazolone, (3) a reddish yellow dyeing is obtained on wool with the product of (1).  Tables are given of other simple and mixed complexes obtainable, and many suitable components for the monoazo dyestuffs are mentioned.  The preferred monoazo dyestuffs are (1) those with a sulphonamide group in R only, particularly when the acyl group contains carbon, hydrogen and oxygen only and R1 is a halogenated aryl group, (2) those with a sulphonamide group in R1 only, Y being-NH-, and (3) bis-sulphonamides of the formula: <FORM:0716753/IV(c)/2> where X is an aryl or aliphatic residue of at least 4 carbon atoms and A is hydrogen, methyl or ethyl. Specification 637,404 is referred to.