Azo dyestuffs, of the general formula <FORM:0448592/IV/1> where R1 is alkyl, aryl, or aralkyl, R2 is a residue of an aromatic amine, which may contain substituents, e.g. halogen or alkyl, sulpho, nitro, hydroxy, carboxy, alkoxy, alkylamino, acylamino, arylamino or aralkylamino groups, R3 is a residue of an aromatic, heterocyclic or aliphatic compound and X is a hydroxy, alkoxy, carboxylic, amino, alkylamino, aralkylamino or arylamino group, are manufactured by diazotizing an amine <FORM:0448592/IV/2> where Ac is an organic acyl residue, coupling in alkaline, neutral or acid medium with a coupling component of the aliphatic, aromatic or heterocyclic series, e.g. of the acetoacetic acid, benzene, naphthalene, anthracene or carbazole series, or an azo dyestuff, containing at least one hydroxy, alkoxy, carboxy, amino or alkylated, aralkylated or arylated amino group and capable of coupling in o-position thereto, and subjecting the product to a treatment with saponifying agents to remove the group Ac. Instead of coupling the diazo-compound with an already prepared azo dyestuff, it is also possible to couple it with a coupling component capable of coupling several times and couple the resulting monoazo dyestuff with any diazo-compound. The group --SO2R1 may be the residue of an alkylsulphonic acid such as methane- or ethanesulphonic acid, or of an arylsulphonic acid such as benzene-, toluene- or naphthalenesulphonic acid, which may be substituted in the aryl nucleus, e.g. by halogen or a nitro, acylamino, alkylamino, hydroxy, alkoxy or carboxylic group, or of an aralkylsulphonic acid such as benzylsulphonic acid or its derivatives. The group Ac may be one of the foregoing residues or the residue of a carboxylic acid, e.g. acetic, formic, benzoic, naphthoic or oxalic acid. The removal of the group Ac may be effected, for example, by heating the dyestuffs with dilute caustic soda lye, or, when coupling has been effected in an alkaline carbonate medium, by simply heating with the mother liquor. The products may be converted into complex metal compounds by treatment in substance or on the fibre with compounds of metals, e.g. chromium or copper. This treatment, especially when performed in alkaline solution, may be combined with the saponification. The dyestuffs dye textile fibres of cellulosic or animal origin yellow to black shades, whilst the metal compounds may be used for dyeing textiles or leather or for the manufacture of lakes and varnishes. In examples: (1) 2-di-p-toluenesulphamino-5-methyl - 1 - aminobenzene is diazotized and coupled with 1 - (4<1> - sulphophenyl) - 3 - methyl - 5-pyrazolone and the product is saponified by heating with caustic soda solution; the product dyes wool from an acid bath yellow shades, becoming brownish red on after-chroming; the coupling component may be replaced by other sulphonated or carboxylated pyrazolones, e.g. by 1-(2<1> : 5<1>-dichloro-4<1>-sulphophenyl) - 3 - methyl - 5 - pyrazolone (greenish yellow shades), by the Neville-Winther acid (orange red shades becoming violet on after-chroming) or by other naphtholmonosulphonic acids, e.g. the 1 : 5-, 1 : 3-, 2 : 6- or 2 : 5- acids; (2) 2-di-p-toluenesulphamino - 5 - methyl - 1 - aminobenzene is diazotized and coupled with 1-naphthol-3 : 6-disulphonic acid and the product is saponified (orange shades becoming violet on after-chroming) ; (3) 2-acetyl-p-toluenesulphamino-5 methyl - 1 - aminobenzene is diazotized and coupled with 1 : 4-naphtholmonosulphonic acid and the acetyl group is removed by saponification (orange-red shades becoming violet on after-chroming) ; (4) 2-di-p-toluenesulphamino - 5 - chloro - 1 - aminobenzene is diazotized and coupled with 2-naphthol-6-sulphonic acid, and the product is saponified (orange-brown shades becoming violet on after-chroming and red by treatment with copper salts); (5) the coupling component of (4) is replaced by 2-naphthol-6 : 8-disulphonic acid; the product dyes wool orange shades becoming red-violet by after-chroming; (6) 2-di-p-toluenesulphamino - 5 - chloro - 1 - aminobenzene is diazotized and coupled with the dyestuff sulphanilic acid --> resorcinol, and the product is saponified; the product dyes wool orange-brown shades becoming brown on after-chroming, and may be transformed by the action of chromium compounds into its chromium compound, which dyes wool brown shades; (7) 2-di-p-toluenesulphamino-1-aminobenzene-5-sulphonic acid is diazotized and coupled with b -naphthol, and the product is saponified (brown-red shades becoming violet on after-chroming); (8) the coupling component of (7) is replaced by m-phenylenediamine (orange shades becoming brown) or by 1-phenyl-3-methyl-5-pyrazolone (yellow shades becoming orange); (9) 2-methanesulphonyl - p - toluenesulphamino - 5 - chloro - 1 - aminobenzene is diazotized and coupled with 1 - naphthol - 4 - sulphonic acid, and the product is saponified by heating in the mother liquor (orange-red shades becoming violet); (10) 2-methanesulphonylethanesulphamino - 5 - methyl - 1 - aminobenzene is diazotized and coupled with 1-(4<1>-sulphophenyl)-3-methyl-5-pyrazolone and the product is saponified as in (9) (yellow shades becoming orange). 2 - Acetyl - p - toluenesulphamino - 5 - methyl - 1 - aminobenzene is obtained by nitration of 1 - methyl - 4 - p - toluenesulphaminobenzene, acetylation, and reduction of the nitro group. 2 - Di - p - toluenesulphamino - 5 - chloro - 1 - aminobenzene is obtained by nitration of 1-chloro-4-p-toluenesulphaminobenzene, treatment with p-toluenesulphochloride, and reduction of the nitro group. 2 - Di - p - toluenesulphamino - 1 - amino - benzene - 5 - sulphonic acid is obtained by nitration of 1 - p - toluenesulphaminobenzene - 4 - sulphonic acid, treatment with p-toluenesulphochloride, and reduction of the nitro-group. 2 - Methanesulphonyl-p-toluenesulphamino - 5 - chloro - 1 - aminobenzene is obtained by nitration of 1 - chloro - 4 - p - toluenesulphaminobenzene, treatment with methanesulphochloride, and reduction of the nitro group. 2 - Methanesulphonylethanesulphamino - 5 - methyl - 1 - aminobenzene is obtained in an analogous manner. The Specification as open to inspection under Sect. 91 comprises also the further diazotization and coupling of such of the products as contain diazotizable amino groups, before or after the saponification step. In connection with the production of metal compounds of the dyestuffs, it is stated that chromium compounds are obtainable by heating the dyestuffs with chromium compounds such as chromium fluoride, acetate, sulphate, formate or hydroxides, or alkali metal chromites, in an aqueous solution or suspension or in the presence of organic solvents, such as glycerine, ethanol or pyridine, and in neutral, acid or alkaline medium, e.g. in the presence of oxalic, acetic, formic or sulphuric acid or of alkali metal carbonates or hydroxides, ammonia or pyridine. The quantity of metal may vary widely. Copper compounds may be similarly obtained by using copper salts or hydroxides and reference is also made to the production of zinc, tungsten, uranium, aluminium, tin, titanium, molybdenum, vanadium, cerium, manganese, iron, cobalt and nickel compounds. Additional examples describe the conversion of the product of (2) and (5) above into their chromium compounds by the action of chromium formate and sulphate respectively, the products dyeing wool red-violet shades. This subject matter does not appear in the Specification as accepted.