US Patent 7122701 Process for preparing aromatic amines

Aromatic amines are produced from aromatic hydrocarbons bya) reacting the aromatic hydrocarbon(s) with a mixture of nitric acid and sulfuric acid to generate a two-phase reaction mixture,b) separating the reaction mixture into an aqueous acid phase and an organic phase containing the nitroaromatic compoundsc) washing the organic phase to purify the nitroaromatic compound(s),d) hydrogenating the nitroaromatic compound(s) in the presence of a catalyst to produce the aromatic amine(s) and water of reaction, ande) separating the water of reaction formed in step d) from the aromatic amine(s),in which the water of reaction separated in step e) is used to wash the organic phase containing the nitroaromatic compounds in step c).