Method for reprocessing reaction mixtures containing diaryl carbonate

US6437166B1 · kind B1 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Carsten Hesse · Krefeld, DE
• Ursula Jansen · Krefeld, DE
• Johann Rechner · Krefeld, DE
• Claus-Peter Reisinger · Wixom, US
• Rob Eek · Bergen op Zoom, NL
• Kaspar Hallenberger · Leverkusen, DE
• Martin Friedrich · Harsum, DE

Key dates

• Filing date: Jun 14, 2001
• Grant date: Aug 20, 2002
• Expiry date: Jun 14, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C68/08
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the work up of reaction mixtures containing diaryl carbonate, aromatic hydroxy compound, water, base and quaternary salt, which are obtained in the preparation of diaryl carbonates by direct carbonylation of aromatic hydroxy compounds, is described. In the process of the present invention an adduct of diaryl carbonate and aromatic hydroxy compound is crystallized from the reaction mixture. A distillate comprising aromatic hydroxy compound is removed from the liquid phase either prior to or after crystallization of the adduct of diaryl carbonate and aromatic hydroxy compound. The liquid phase remaining after the crystallization and distillation steps may be recycled, without further work up, back to the direct carbonylation process step by which the diaryl carbonate is initially prepared.