Bayer Aktiengesellschaft

Fred Schuhmacher

Adolf Brill

Henry Giera

Adolf Sicheneder

Torsten Pohl

Uwe Hugger

Klaus Reinartz

The present invention relates to the production of aminodiphenyl-amines resulting in good yields and high purity levels when aromatic amines are reacted with nitrohalobenzenes in the presence of a palladium catalyst and a base and the product thus obtained is subsequently hydrogenated with hydrogen.

Process for producing aminodiphenylamines

4-Aminodiphenylamines are produced by reacting optionally substituted aniline with optionally substituted nitrobenzene in the presence of water and/or alcohols and organic and/or inorganic bases and then catalytically hydrogenating the resultant nitro- and/or nitrosodiphenylamine in the presence of water, wherein the catalytic hydrogenation of the reaction mixture is performed in the presence of 25 to 80 wt. % of water, relative to the weight of the reaction mixture from the condensation reaction, the hydrogenation catalyst is removed from the hydrogenation mixture once absorption of hydrogen has ceased, 10 to 100 vol. % of aromatic solvent, relative to the total volume of the hydrogenation mixture, are optionally added to the hydrogenation mixture, the resultant organic phase is separated in order to isolate the 4-aminodiphenylamine and the aqueous phase is returned to the initial reaction mixture.

Process for the production of optionally substituted

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Schenefeld, Germany

Fred Schuhmacher