Process for the production of optionally substituted 4-aminodiphenylamines

US5739403A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Klaus Reinartz · Cologne, DE
• Adolf Brill · Brunsbüttel, DE
• Fred Schuhmacher · Schenefeld, DE

Key dates

• Filing date: Jan 6, 1997
• Grant date: Apr 14, 1998
• Expiry date: Jan 6, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C209/68
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

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.