Azo dyes are made by coupling diazotized 1-amino-2-cyano-4-nitrobenzene or 1-amino-2-cyano-4 : 6-dinitrobenzene with a component of the formula ANRR<1>, where A is a benzene or naphthalene nucleus, which may be substituted, and R and R<1> are hydrogen atoms or alkyl, aryl or aralkyl groups, the coupling conditions being so selected that the group --NRR<1> is the group that causes coupling. Such of the products as contain a hydroxy or a primary or secondary amino group may be acylated or alkylated, if desired. The coupling components include compounds of the formula above in which R or R<1> is (a) a simple alkyl group, such as methyl, ethyl, propyl or butyl, or (b) a halogenalkyl group such as a chloro-, bromoor iodo-ethyl group, or (c) a hydroxyalkyl group, such as an oxyethyl, oxypropyl, oxybutyl or dioxypropyl group, or (d) an etherified or esterified hydroxyalkyl group such as an acetoxyethyl group or an ethylsulphuric acid residue, or (e) an alkylcarboxylic acid residue or a derivative thereof, such as a propionic acid residue, a propionamide or propionic ester residue or a cyanoethyl or sulphocyanoethyl residue; when R or R<1> is an aryl or aralkyl group the aryl nucleus may be substituted. Specified coupling components are aniline, the naphthylamines, N - methoxyethylaniline, N-ethyl - N - methoxyethylaniline, 3 - methyl - N-ethyl - N - methoxyethylaniline, 2 - methoxy - 5-methyl - N - methoxyethylaniline, 2-methoxy - 5-methyl - N - ethyl - N - methoxyethylaniline, 2-methoxy-5-methyl - N - butyl - N - methoxyethylaniline, 2 - methoxy - 5 - methyl - N - di(methoxyethyl)aniline, 2 : 5 - dimethoxy - N - methoxyethylaniline, 2 : 5 - dimethoxy - N - di(methoxyethyl)aniline, N - methoxyethyl - 1 - naphthylamine, N - methoxyethyl - 2 - naphthylamine, N - ethyl - N - oxyethylaniline, N - butyl - N - oxyethylaniline, 3 - methyl - N -ethyl - N - oxyethylaniline, 3-methyl - N - butyl - N - oxyethylaniline, 2 - methoxy - 5 - methyl - N - oxyethylaniline, 2-methoxy -5-methyl-N-ethyl-N-oxyethylaniline, 2-methoxy-5-methyl-N - methoxyethyl-N -oxyethylaniline, 2-methoxy-5-methyl-N-butyl-N-oxyethylaniline, 2 - methoxy - 5 - methyl - N-di(oxyethyl)aniline, 2 : 5 - dimethoxy - N - oxyethylaniline, 2 : 5-dimethoxy-N-ethyl-N-oxyethylaniline, 2 : 5-dimethoxy-N-methoxyethyl-N-oxyethylaniline, 2 : 5-dimethoxy-N -di(oxyethyl)aniline, N-oxyethyl-1-naphthylamine, N-oxyethyl-2-naphthylamine, N-ethyl-N-acetoxyethylaniline, 2 - methoxy - 5 - methyl - N - di-(acetoxyethyl)aniline, 2-methoxy-5-methyl-N-ethyl-N-acetoxyethylaniline, 2 : 5-dimethoxy-N - ethyl - N - acetoxyethylaniline, 2 : 5-dimethoxy - N - di(acetoxyethyl)aniline, 2-methoxy-5-methyl-N-methoxyethyl-N-dioxypropylaniline, 2-methoxy - 5 - methyl - N - oxyethyl - N - dioxypropylaniline, 2 - methoxy - 5 - methyl-N-oxyethyl-N-g -ethoxy-b -oxypropylaniline, 2-methoxy-5-methyl-N-oxyethyl-N-g -methoxy - b - oxypropylaniline, 2-methoxy - 5-methyl - N - butyl - N - g - ethoxy - b - oxypropylaniline, 2-methoxy-5-methyl-N-butyl-N-g -methoxy-b -oxypropylaniline, 2 : 5-dimethoxy-N-methoxyethyl - N - dioxypropylaniline, 2 : 5-dimethoxy - N - oxyethyl - N - dioxypropylaniline, 2 : 5-dimethoxy-N-oxyethyl-N-g -ethoxy-b -oxypropylaniline, 2 : 5-dimethoxy-N-oxyethyl-N-g - methoxy - b - oxypropylaniline, 2 : 5-dimethoxy-N-butyl-N-g -ethoxy-b -oxypropylaniline, 2 : 5-dimethoxy-N-butyl-N-g -methoxyethyl - b - oxypropylaniline, N - butyl - N - g -methoxy - b - oxypropylaniline, 3 - methyl - N-butyl-N-g -methoxy - b - oxypropylaniline, N-butyl - N - g - ethoxy - b - oxypropylaniline, 3-methyl-N-butyl-N-g -ethoxy-b -oxypropylaniline, N -di(oxyethyl)-aniline, 3-methyl- N - di(oxyethyl)-aniline, 3-chloro-N-di(oxyethyl)-aniline, N-di(dioxypropyl)-aniline, 3-chloro-5-methoxy-N - di(oxyethyl)-aniline, 1-amino-5-naphthol, 1 - amino-6-naphthol, 1-amino-7-naphthol, 1-amino-8-naphthol, 2-amino-3-naphthol, 2-amino-4-naphthol, 2-amino-5-naphthol, 2-amino-6-naphthol, 2-amino-7-naphthol, 2-amino-8-naphthol, and alkylaminonaphthols such as 1 - methylamino - 5-naphthol and 1 - oxyethylamino - 5 - naphthol; sulphonic acids and sulphuric esters of these compounds may also be used. The products are red, brown, violet, blue or green dyes applicable to wool, silk, cellulose, and artificial silk, particularly of cellulose esters or ethers such as acetyl- or nitro-cellulose. Thus, dispersions of non-sulphonated dyes, prepared by grinding the dyes in water with a dispersing agent such as a sulphonated residue from the manufacture of benzaldehyde or turpentine oil, may be used for dyeing acetate artificial silk; alternatively, such dispersions may be treated with a further amount of the same or another dispersing agent, such as sulphite cellulose lye, and then dried in vacuo. In the examples: (1) 2-cyano-4-nitraniline is diazotized with a solution of sodium nitrite in concentrated sulphuric acid, and the solution is partly neutralized and coupled with N - ethyl - N-methoxyethylaniline; (2) diazotized 2-cyano-4-nitraniline is coupled with 2-methoxy-5-methyl-N - di(methoxyethyl) - aniline; (3) diazotized 2-cyano-4-nitraniline is coupled with 3-methyl-N - butyl - N - oxyethylaniline; (4) diazotized 2-cyano-4-nitraniline is coupled with 1-amino-5-naphthol; (5) 6-cyano-2 : 4-dinitraniline is diazotized as in example 1 and coupled with 2 - methoxy - 5 - methyl - N - di(methoxyethyl)-aniline or 2-methoxy-5-methyl-N-butyl-N-methoxyethylaniline; (6) diazotized 6-cyano-2 : 4 - dinitraniline is coupled with 2 : 5-dimethoxy - N - di(methoxyethyl) - aniline; (7) diazotized 6-cyano-2 : 4-dinitraniline is coupled with 2-methoxy-5-methyl - N - oxyethyl - N - methoxyethylaniline; (8) diazotized 6-cyano-2 : 4-dinitraniline is coupled with 3-methyl-N-butyl - N - oxyethylaniline; (9) diazotized 2-cyano-4-nitraniline is coupled with 2-amino-8-naphthol-6-sulphonic acid or an N-alkyl or N-aryl derivative thereof to yield blue or violet dyes for wool; (10) the product of example 4 is pasted with a dispersing agent such as turkey red oil, sulphite cellulose lye, or a sulphonated residue from the manufacture of benzaldehyde, and a dyebath for acetate silk is prepared by diluting the paste and adding soap solution; dyeing is then effected at a temperature rising to 85 DEG C. Amines.--The etherified or esterified N-hydroxyalkyl arylamines specified above are obtainable by the methods described in British Specification 422,843 (or French Specification 758,079). 6-Cyano-2 : 4-dinitraniline is obtainable by nitrating 6-cyano-1-methoxybenzene or 6-cyano-4-nitro-1-methoxybenzene, and treating the 6-cyano-2 : 4 - dinitro - 1 - methoxybenzene so obtained with ammonia in methyl alcohol, whereby the methoxy group is replaced by an amino group. The Specification as open to inspection under Sect. 91 refers to the use, as diazo components, of substitution products in general of 1-amino-2-cyano-4-nitro- (or 4 : 6-dinitro-) benzene, and specifies the hydroxy and alkoxy substitution products and also 1-amino-2-cyano-6-chloro-(or bromo- or iodo-)-4-nitrobenzene. This subject-matter does not appear in the Specification as accepted.