Patent GB-634390-A (GB)
Title: Manufacture of new intermediate products and azo-dyestuffs
IPC: C09B29/20
Filed: 1947-02-26
Abstract: Aminohydroquinone ethers of the general formula <FORM:0634390/IV (b)/1> (wherein X and Y represent different aliphatic hydrocarbon radicals) are manufactured by treating a compound of the general formula <FORM:0634390/IV (b)/2> with a dilute caustic alkali at 100-150 DEG  C. under pressure so as to converting the amino group into a hydroxy group, treating the product (preferably in the form of an alkali metal phenate) with an alkylating or alkenylating agent corresponding to the radical Y (e.g. an alkyl or alkenyl halide, such as a bromide or especially a chloride, or a dialkyl sulphate), and reducing the nitro group to an amino group (e.g. by means of iron in alcoholic solution).  Advantageously X is a radical containing only a small number of carbon atoms (e.g. ethyl, propyl or especially methyl) and Y is a different radical containing 2-5 carbon atoms (e.g. ethyl, propyl, isopropyl, allyl, butyl or amyl), or it may also be methyl.  An example and a table illustrate the production of compounds having some of the above meanings for X and Y. 3-Nitro-4-aminophenol ethers of the second general formula above are obtainable by nitrating the corresponding ether of a 4-acylamino- (e.g. formylamino-, acetylamino- or benzoylamino-) phenol and hydrolysing the acylamino group.  The nitration may be effected with dilute nitric acid or in an organic solvent (e.g. glacial acetic acid, chlorobenzene or nitrobenzene), yielding a mixture of the 2-and 3-nitro compounds which is subjected to hydrolysis (e.g. in dilute caustic alkali at about 70 DEG  C.), whereby the latter compound is hydrolysed whilst the former is practically unattacked and may be dissolved out with water, in which it has the greater solubility.  3 : 2-Hydroxynaphthoic acid arylides are manufactured by condensing an aminohydroquinone ether of the first general formula above with a 2-hydroxynaphthalene containing in the 3-position a carboxyl or functionally converted carboxyl group (e.g. with a 2 : 3-hydroxynaphthoic acid halide or with the acid itself in the presence of a phosphorus halide).  In an example, 2 : 3-hydroxynaphthoic acid is heated in chlorobenzene in the presence of phosphorus trichloride with 2-aminohydroquinone 1-ethyl, propyl, allyl or butyl 4-methyl ether.ALSO:Azo dyes; azo dyes, forming upon the material.-Azo dyes are manufactured in substance or on the fibre by coupling a 2 : 3-hydroxynaphthoic acid arylide of the general formula <FORM:0634390/IV (c)/1> (wherein X and Y represent different aliphatic hydrocarbon radicals) with a diazo (or diazoazo) compound free from sulphonic acid groups, e.g. one suitable for the production of ice-colours, especially a diazotized halogenated aniline (which yields brownish dyeings).  The dyestuffs produced in substance are useful as pigments, e.g. for colouring artificial masses such as phenoplasts, aminoplasts or spinning masses.  Components specified in examples and tables are:- diazo components: 4-chloro-2-aminoanisole, 2 : 5-dichloraniline, o-nitraniline, m-chloraniline, 4-nitro-2-aminoanisole, 4-chloro-2-amino-1 : 11-diphenyl ether, 4-chloro-2-aminotoluene, 4 - amino - 3 : 21 - dimethyl - 1 : 11 - azobenzene, 4-benzoylamino-5-methyl-2-methoxyaniline, 4 - benzoylamino - 2 : 5 - diethoxyaniline and 4 - methoxy - 2 - nitraniline; coupling components: 1-(21 : 31-hydroxynaphthoyl)-amino-2-ethoxy-, -propoxy- and -butoxy-5-methoxybenzene.  Secondary diazo dyes may also be made by coupling a diazo compound with an amine of the general formula <FORM:0634390/IV (c)/2> (wherein X and Y represent different aliphatic hydrocarbon radicals), rediazotizing and coupling with an end component.