Process for the preparation of multinuclear aromatic polyamines

US4914236A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Hartmut Knofel · Odenthal, DE
• Michael Brockelt · Bensberg, DE
• Marcel Petinaux · Krefeld, DE
• Rudolf Uchdorf · Shanghai, CN

Key dates

• Filing date: Apr 25, 1988
• Grant date: Apr 3, 1990
• Expiry date: Apr 25, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C209/78
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to an improved process for the preparation of multinuclear aromatic polyamines by the condensation of aniline with formaldehyde in the presence of water and acid catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent. The acid catalyst obtained in the aqueous phase of extraction is reused.