Quinone-(1 : 4)-diazides are made by diazotizing the sulphonic and carboxylic acid amides of p-amino-phenols and p-amino-naphthols in a mineral acid medium, when the diazides are formed directly in most cases, or, if diazonium salts are first formed, these are converted by subsequent treatment with alkalis. Particular compounds are: Benzoquinone - (1 : 4) - diazide - (4) - 2 - sulphonanilide (example 1) made by reacting 1-chloro - 4 - nitrobenzene - 2 - sulphochloride with aniline in dioxane, heating the resulting 1-chloro - 4 - nitrobenzene - 2 - sulphonanilide with caustic potash to form 1-hydroxy-4-nitrobenzene - 2 - sulphonanilide, reducing this to the corresponding amino compound and diazotizing the latter. Benzoquinone - (1 : 4) - diazide - (4) - 2 - (N - b -naphthyl) - sulphonamide (example 2) made by procedure as that of example 1 using b -naphthylamine instead of aniline. N : N1 - di - (benzoquinone - (1 : 4) - diazide-(4) - 2 - sulphonyl) - p - phenylene - diamine (example 3) made by procedure as that of example 1 using p-phenylene-diamine instead of aniline. Benzoquinone - (1 : 4) - diazide - (4) - 2 -benzoic-acid anilide (example 4) made by diazotizing the (amino) reduction product of 1-hydroxy - 4 - nitro - 2 - benzoic - acid anilide. Benzoquinone-(1 : 4)-diazide-(4)-2-benzoic acid-N-ethyl-anilide (example 5) made by nitration, reduction and diazotization of salicylic-acid-N-ethyl anilide. Benzoquinone-(1 : 4)-diazide-(4)-2-benzoic acid-21 : 51-dimethyl anilide (example 6) made, similarly to example 6, from salicylic acid-2 : 5-dimethyl anilide. Benzoquinone-(1 : 4)-diazide-(4)-2-benzoic acid-b -naphthylamide (example 7) made by condensing 1 - chloro - 4 - nitrobenzene - 2 - carboxylic acid with b -naphthylamine, heating the product with sodium acetate and acetamide, dissolving with caustic soda, and acidifying to produce 1 - hydroxy - 4 - nitro - benzoic acid naphthylamide which is reduced and diazotized. 6 - Methyl - benzoquinone - (1 : 4) - diazide-(4) - 2 - benzoic - acid - b - naphthylamide (example 8) made by nitration, reduction and diazotization of 3-methyl-2-hydroxy-1-benzoic-acid-b -naphthylamide N : N - di - (benzoquinone - (1 : 4) - diazide- (4) - 2 - benzoyl) - p - phenylene - di-amine (example 9) made, similarly to example 8, from the reaction product of salicyclic acid and p-phenylene diamine. Benzoquinone - (1 : 4) - diazide - (4) - 2 - carboxylic - acid - phenyl - ester (example 10) made, similarly to example 8, from 5-nitro-salicylic-acid-phenyl ester. Benzoquinone - (1 : 4) - diazide - (4) - 2 - carboxylic acid - b - naphthyl ester (example 11) made, similarly from the naphthyl ester corresponding to the phenyl ester used in example 10. Benzoquinone - (1 : 4) - diazide - (4) - 2 - (N-dichlorophenyl) - sulphonamide (example 12) made, as in example 1, from 1-chloro-4-nitrobenzene - 2 - sulphochloride and 2 : 4 - dichloraniline. Benzoquinone - (1 : 4) - diazide - (4) - 2 - (N.a -naphthyl) - sulphonamide (example 13) made analogously to example 2. 2 - Chloro - benzoquinone - (1 : 4) - diazide - (4)-5 - (N - phenyl) - sulphonamide (example 14) made from the corresponding chlorsulphonic acid and aniline. 6 - Bromo - benzoquinone - (1 : 4) - diazide - (4)-2 - (N - phenyl) - sulphonamide (example 15) made by bromination of the sulphonanilide of example 1. Benzoquinone - (1 : 4) - diazide - (4) - 2 - sulphonic-acid-phenyl ester (example 16) made by heating 1 - chloro - 4 - nitrobenzene - 2 - sulphonic acid-phenyl ester with sodium acetate and acetamide, extracting the 1-hydroxy derivative produced with ether and reducing and diazotizing this. Benzoquinone - (1 : 4) - diazide - (4) - 2 - (N - 41-methoxy - phenyl) - sulphonamide (example 17) made as in example 1 using 4-amino-anisole in place of aniline. 2 - Phenyl - benzoquinone - (1 : 4) - diazide and benzoquinone - (1 : 4) - diazide - 2 - phenyl - sulphone (example 18) made as regards the former by diazotization of 2 - phenyl - 1 - hydroxy - 4-amino-benzene; and the latter by Friedel-Craft reaction between 1-chloro-4-nitro-benzene-2-sulphochloride and benzene to form the corresponding - 2 - phenyl - sulphone, which latter is converted to the 1-hydroxy derivative and then reduced and diazotized. Naphthoquinone - (1 : 4) - diazide - (4) - 2-sulphon - b - naphthylamine (example 19) made by heating b -naphthylamine with naphthoquinone - (1 : 4) - diazide - (4) - 2 - sulphochloride which is itself made by reacting 1-hydroxy - naphthalene - 2 - sulphonic acid with nitrous acid, reducing and then diazotizing the nitroso compound formed, and heating the product with chlorsulphonic acid. Naphthoquinone - (1 : 4) - diazide - (4) - 2-sulphon - 2 - amino fluorene compound (example 20) made analogously to example 19, using 2-amino-fluorene in place of b -naphthylamine. Naphthoquinone - (1 : 4) - diazide - (4) - 2-carboxylic acid anilide (example 21) made by diazotizing 4 - amino - 1 - naphthol - 2 - carboxylic acid anilide, which itself can be obtained by reducing the azo dye derived from diazotized aniline and 1-naphthol-2-carboxylic acid anilide. Naphthoquinone - (1 : 4) - diazide - (4) - 2-sulpho - p - tolyl ester (example 22) made by reacting the corresponding sulphochloride with p-cresol. The reaction product of 4 : 41-diamino-diphenylmethane and naphthoquinone - (1 : 4) - diazide - (4) - 2 - sulphochloride (example 23). The reaction product of 71-hydroxy-naphtho-2-ethyl - N - n - propyl - 11 : 21 : 4 : 5 - imidazole and naphthoquinone - (1 : 4) - diazide - (4) - 2 - sulphochloride (example 24). Naphthoquinone - (1 : 4) - diazide - (4) - 2-sulphon-benzylamide (example 26) made analogously to example 19. Naphthoquinone - (1 : 4) - diazide - (4) - 2-sulphon - N - n - butylamide (example 27) made analogously to example 19. Naphthoquinone - (1 : 4) - diazide - (4) - 2-sulphon - 2 - benzimidazolylamide (example 28) made analogously to example 19. Specification 633,796, [Group XVI], is referred to.ALSO:Diazotized aniline is coupled with 1-naphthol-2-carboxylic acid aniline. Specification 633,796, [Group XVI], is referred to.