Azo dyes; azo dyes, forming upon the material; cellulose esters and ethers, dyeing; acid wool dyes without mordants, dyeing with; printing.--Azo dyes are manufactured by coupling a diazocompound of an amine of the formula <FORM:0457679/IV/1> where R is an alkyl or aralkyl group and in which the p-position to the amino-group does not contain a nitro- or acylamino-group, with a component which contains as the group directing coupling a substituted or unsubstituted amino-group. The products dye animal fibres or cellulose esters and ethers, e.g. acetate artificial silk, yellow to red, blue-red or violet shades, those containing a sulphonic acid group being suitable for dyeing animal fibres, e.g. wool in acid baths, or for printing acetate artificial silk, whilst those free from sulphonic acid groups are suitable for dyeing acetate artificial silk, preferably after being brought into a finely dispersed condition, e.g. by grinding with dispersing agents such as sulphite cellulose lye or the sulphonated residue of the benzaldehyde manufacture. The products are particularly suitable for the production of combination dyeings. Examples describe the production of the following dyestuffs: (1) 1-aminobenzene-2-methyl-sulphone --> N-ethyl-N-p-sulphobenzylaniline; the product yields yellow-orange prints on acetate artificial silk and dyes wool orange shades; (2) 1-aminobenzene-2-methyl-sulphone --> 2-amino-8-naphthol-6-sulphonic acid; the product dyes wool red shades; the diazo-component may be replaced by 1-amino-5-chlorobenzene-2-methyl-sulphone, yielding a somewhat bluer red; (3) 1-aminobenzene-2-benzyl-sulphone --> 2 : 8 : 6-acid; the product dyes wool blue-red shades; (4) 1-aminobenzene-2-methyl-sulphone --> p-cresidine; the product dyes acetate artificial silk golden yellow shades; the diazo-component may be replaced by 1-aminobenzene-2-ethyl-sulphone and the coupling component by dimethylaniline; the dyeings may be diazotized on the fibre and developed, e.g. with 1 - phenyl - 3 - methyl - 5 - pyrazolone, resorcinol, p-cresotinic acid, b -naphthol, 2 : 3-oxynaphthoic acid, ethyl-a - or b - naphthylamine; (5) 1 - aminobenzene - 2 - methyl-sulphone-4-sulphonic acid --> b -naphthylamine; the product dyes wool orange red tints; if as coupling component there is used 2-ethylaminonaphthalene, the product yields blue - red dyeings; (6) 1 - aminobenzene - 2 - methyl-sulphone-4-sulphonic acid --> 2-amino-8-naphthol; the product dyes wool red-violet shades. In a further example: (7) wool is dyed with the product of (2) from a bath containing sodium sulphate and sulphuric acid. Other components specified are: diazo-components: 1-aminobenzene - 2 - propyl-, -butyl-and -chlorobenzyl-sulphones, 1-aminobenzene-2-ethyl- and -benzyl-sulphone-4-sulphonic acids and 1 - amino - 5 - chlorobenzene - 2 - methyl - sulphone-4-sulphonic acid; coupling components: a -naphthylamine, a - and b -naphthylamine-sulphonic acids, ethyl - b - naphthylaminesulphonic acids, aminonaphthols, e.g. 1 : 5-amino-naphthol and its sulphonic acids, N-alkyl and -aryl derivatives of 2 : 8-aminonaphthol and its 6-sulphonic acid, e.g. phenyl - 2 : 8 : 6 - acid, diphenylamine and its sulphonic acids, alkylanilines, e.g. ethylbenzylaniline, aniline, o- and m-toluidine, p-xylidine, 2 : 5-dioxyalkylaminobenzenes, amines which are alkylated or oxyalkylated in the amino-group and also oxyalkylated amines in which the oxy-group is capable of being etherified or esterified. Aminosulphones of the general formula given above are obtainable by reducing 2 : 2<1>-dinitrodiphenyl disulphide or a substitution product thereof, e.g. a halogen substitution product, to the o-nitrothiophenol, converting this into an alkyl or aralkyl thioether, e.g. by the action of an alkyl or aralkyl halide, oxidizing to the corresponding sulphone and reducing the nitro-group. Alternatively, the alkyl halide may be replaced by an a -halogen fatty acid, e.g. chloracetic or a -chloropropionic acid, in which case an additional step of splitting of carbon dioxide is effected after the oxidation to the sulphone. 1 - Aminobenzene - 2 - methyl - sulphone - 4 - sulphonic acid is obtainable by heating the acid sulphate of 1-aminobenzene-2-methyl-sulphone to 190--200 DEG C.