A method of producing 4-aminodiphenylamine or substituted derivatives thereof comprising the steps of: (a) bringing an aniline or aniline derivative selected from the group consisting of formanilide, phenylurea, carbanilide and thiocarbanilide, or from the group consisting of 2-methoxyaniline, 4-methoxyaniline, 4-chloroaniline, p-toluidine, 4-nitroaniline, 3-bromoaniline, 3-bromo-4-aminotoluene, p-aminobenzoic acid, 2, 4-diaminotoluene, 2,5-dichloroaniline, 1,4-phenylene diamine, 4,4'-methylene dianiline, 1,3,5-triaminobenzene, and mixtures thereof, into reactive contact with nitrobenzene; (b) obtaining a 4-aminodiphenylamine intermediate product by reacting the aniline or aniline derivative and nitrobenzene in a confined zone at a suitable time, pressure and temperature in the presence of a mixture comprising an organic base, and an inorganic salt or a metal organic salt, or mixtures thereof, selected from the group consisting of fluoride, chloride, bromide, sulfate, hydrogen sulfate, nitrate, phosphate, dihydrogen phosphate, formate, acetate, oxalate, malonate, citrate, tartrate, maleate, chlorate, perchlorate, chromate, rhenate and carbonate salts of cesium, rubidium, potassium and sodium, and mixtures thereof, and an oxidant, wherein the organic base is selected from the group consisting of tetramethylammonium hydroxide, tetrabutylammonium hydroxide, methyltributylammonium hydroxide, benzyltrimethylammonium hydroxide, tricaprylmethylammonium hydroxide, cetyltrimethylammonium hydroxide, and choline hydroxide; and (c) reducing the 4-aminodiphenylamine intermediate product of step (b) to produce 4-aminodiphenylamine or substituted derivatives thereof. (a) bringing an aniline or aniline derivative selected from the group consisting of formanilide, phenylurea, carbanilide and thiocarbanilide, or from the group consisting of 2-methoxyaniline, 4-methoxyaniline, 4-chloroaniline, p-toluidine, 4-nitroaniline, 3-bromoaniline, 3-bromo-4-aminotoluene, p-aminobenzoic acid, 2, 4-diaminotoluene, 2,5-dichloroaniline, 1,4-phenylene diamine, 4,4'-methylene dianiline, 1,3,5-triaminobenzene, and mixtures thereof, into reactive contact with nitrobenzene; (b) obtaining a 4-aminodiphenylamine intermediate product by reacting the aniline or aniline derivative and nitrobenzene in a confined zone at a suitable time, pressure and temperature in the presence of a mixture comprising an organic base, and an inorganic salt or a metal organic salt, or mixtures thereof, selected from the group consisting of fluoride, chloride, bromide, sulfate, hydrogen sulfate, nitrate, phosphate, dihydrogen phosphate, formate, acetate, oxalate, malonate, citrate, tartrate, maleate, chlorate, perchlorate, chromate, rhenate and carbonate salts of cesium, rubidium, potassium and sodium, and mixtures thereof, and an oxidant, wherein the organic base is selected from the group consisting of tetramethylammonium hydroxide, tetrabutylammonium hydroxide, methyltributylammonium hydroxide, benzyltrimethylammonium hydroxide, tricaprylmethylammonium hydroxide, cetyltrimethylammonium hydroxide, and choline hydroxide; and (c) reducing the 4-aminodiphenylamine intermediate product of step (b) to produce 4-aminodiphenylamine or substituted derivatives thereof.