Process for the production of polynuclear aromatic polyamines

US4924028A · 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 6, 1989
• Grant date: May 8, 1990
• Expiry date: Apr 6, 2009

Classification

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

Abstract

This invention relates to an improved process for the preparation of polynuclear aromatic polyamines in which the reaction product is prepared by condensing aniline with formaldehyde in the presence of water and acidic catalysts and is worked up by extraction with a hydrophobic solvent. The acid catalyst that accumulates in the aqueous phase during the extraction process is reused.