Process for preparing diaryl carbonates

US5502232A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Hans-Josef Buysch · Krefeld, DE
• Joachim Dohm
• Carsten Hesse · Krefeld, DE
• Johann Rechner · Krefeld, DE
• Dieter Kaufmann · Heidenheim, DE

Key dates

• Filing date: Nov 15, 1994
• Grant date: Mar 26, 1996
• Expiry date: Nov 15, 2014

Classification

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

Abstract

Diaryl carbonates can be prepared by reacting aromatic hydroxy compounds with CO and O.sub.2 at elevated temperature over a noble metal catalyst in the presence of a base, a quaternary salt, a cocatalyst and a dessicant. According to the invention, the noble metal catalyst is activated with CO in the presence of the quaternary salt and optionally in the presence of the cocatalyst. In a particular process variant, the base used is a preformed alkali metal phenoxide.