Process for the production of polynuclear aromatic polyamines

US5359141A · 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
• Hans-Peter Schal · Dormagen, DE

Key dates

• Filing date: Apr 6, 1992
• Grant date: Oct 25, 1994
• Expiry date: Apr 6, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/584
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to an improved process for the production of polynuclear aromatic polyamines by condensation of aniline with formaldehyde in the presence of water and acidic catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent, the acid catalyst accumulating in the aqueous phase of the extraction step being reused.