Method of extractive separation of diaryl carbonates and the original aromatic hydroxy compounds from reaction solutions

US5712406A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Hans-Josef Buysch · Krefeld, DE
• Carsten Hesse · Krefeld, DE
• Johann Rechner · Krefeld, DE

Key dates

• Filing date: Feb 5, 1997
• Grant date: Jan 27, 1998
• Expiry date: Feb 5, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C68/01
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Diaryl carbonate and an aromatic hydroxy compound are simultaneously separated from a crude reaction mixture for producing diaryl carbonates by oxidative carbonylation of the aromatic hydroxy compound and containing the diaryl carbonate and excess hydroxy compound together with the catalyst system, consisting of a noble-metal catalyst, co-catalyst, quaternary salt and a base. The crude reaction mixture is mixed with a covalent aprotic extraction agent, a phase separation is carried out into a donor phase containing the catalyst system and a recipient phase containing the diaryl carbonate and the hydroxy compound in concentrated form, and the diaryl carbonate and the hydroxy compound are isolated from the recipient phase.