Arylides of 4-hydroxydiphenyl-3-carboxylic acid are manufactured by condensing the acid or its chloride with an arylamine which does not contain sulphonic or carboxylic acid groups, e.g. aniline or its homologues, polynuclear arylamines such as naphthylamines, alkoxyarylamines, halogen or nitro-substitution products of the said arylamines, diamines, such as those of the benzene, diphenyl or naphthalene series or diamines derived from a ring system having rings connected by an intermediate member, such as diaminodiphenylamine or diaminocarbazole. In examples, 4-hydroxydiphenyl-3-carboxylic is reacted in toluene solution, in the presence of phosphorus trichloride, with (1) aniline, (2) dianisidine. A table (I) gives the properties of the products obtained by condensation with 1-amino-2-methoxybenzene, 1-amino-2-, 3- and 4-methylbenzene, 1-amino2:4-dimethylbenzene, 1-amino-4-chlorobenzene, 2-aminonaphthalene, 3 : 6-diaminocarbazole, 1 : 4-diaminobenzene, 4 : 4<1>-diaminostilbene, 4 : 4<1>-diaminodiphenylmethane, 1 : 5-diaminonaphthalene, and 1-amino-4-nitrobenzene. Azo dyes; azo dyes, forming upon the material; lakes.--Azo dyes are manufactured by coupling an arylide of 4-hydroxydiphenyl-3-carboxylic acid in substance, on the fibre, or in the presence of a substratum, with a diazo-, tetrazo- or diazoazo-compound, neither component containing solubilizing groups. In examples: (3) cotton piece goods are impregnated with 4 - hydroxydiphenyl - 3 - carboylaminobenzene and developed with diazotized 1-amino-2-(4<1>-chlorophenoxy) - 5 - chlorobenzene yielding a green-olive dyeing; there is similarly obtained from diazotized 1-amino-2-phenoxy-5-chlorobenzene, a green-olive with 4-hydroxydiphenyl-3-carboyl-(1<1>-amino-4<1>-chlorobenzene) and a brown-olive with 4-hydroxydiphenyl-3-carboyl-(1<1>-amino-2<1> -methoxybenzene); (4) cotton yarn is impregnated with bis-(4-hydroxydiphenyl-3-carboyl) - 4<1> - 4<11> - diamino - 3<1>: 3<11> - dimethoxydiphenyl and developed with diazotized 1-amino-2 : 5-dichlorobenzene or 1-amino-2-(2<1> : 5<1>-dichlorophenoxy) - 5 - chlorobenzene, yielding yellowish brown dyeings; (5) the dyestuff 1-amino-2 : 5-dichlorobenzene --> 4-hydroxydiphenyl - 3 - carboyl - (1<1> - aminonaphthalene) is produced in substance. A table (II) gives the tints obtained with additional dyestuffs, employing as additional coupling components certain of the arylides described in table (I) and also the arylides from 1-amino-2 : 5-dimethoxybenzene and 1-amino-3-nitrobenzene, and employing the following additional diazo components : 4 - amino - 3 : 2<1> - dimethyl - 1 : 1<1>-azobenzene, 4 - amino - 4<1> - methoxydiphenylamine, 4 : 4<1> - diamino - 3 : 3<1> - dichlorodiphenyl, 4 : 4<1> - diamino - 3 : 3<1> - dimethoxydiphenyl, 1 - amino - 4 - benzoylamino - 2 : 5-dichlorobenzene, 1-amino-4-(2<1> : 5<1>-dichlorophenoxy)-3-chlorbenzene, 1-amino-2 : 4 : 5-trichlorobenzene, 1-amino-4-nitronaphthalene, 1-amino-2-methyl-4-nitrobenzene, 1-amino-4-benzoylamino - 3 - methoxy - 6 - chlorobenzene, 1-amino-2-chloro-4-nitrobenzene, 1-amino-4-methyl-2-nitrobenzene, 1-amino-2-methoxy-4-nitrobenzene, 1-amino-3-methyl-2 : 4-dichlorobenzene, 1-amino-2-phenylsulphonylbenzene, 1 - amino - 2 - chloro - 5 - trifluoromethylbenzene, 1 - aminoanthraquinone, 4 - amino - 2 : 5-dimethoxy - 4<1> - nitroazobenzene, 1 - amino - 4 - benzoylamino - 2 : 5 - diethoxybenzene and 1-amino-2-methyl-5-chlorobenzene. 1-Amino-2-(2<1> : 5<1>-dichlorophenoxy)-3-chlorobenzene are manufactured by condensing 1 : 4-dichloro-2-nitrobenzene and 3 : 4-dichloro-1-nitrobenzene respectively with a 2 : 5-dichlorophenolate and reducing the nitro-group.