Process for the preparation of toluenediamines by catalytic hydrogenation of dinitrotoluenes

US7511176B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Fritz Pohl · Wittmund, DE
• Wolfgang Lorenz · Dormagen, DE
• Lars Padeken · Itzehoe, DE
• Bernd Pennemann · Moitzfeld, DE
• Friedhelm Steffens · Leverkusen, DE
• Gerhard Wiechers · Leverkusen, DE

Key dates

• Filing date: Dec 13, 2007
• Grant date: Mar 31, 2009
• Expiry date: Dec 13, 2027

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C209/36
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for the preparation of toluenediamine, in which dinitrotoluene is reacted with hydrogen in the presence of a catalyst. The dinitrotoluene required by this process has a content of carbon dioxide, in either physically dissolved or chemically bonded form, of not more than 0.175 mol %, based on the molar amount of the dinitrotoluene.