Process for the preparation of diaryl carbonates

US5344954A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Norbert Schon · Krefeld, DE
• Hans-Josef Buysch · Krefeld, DE
• Paul Wagner · Mülheim an der Ruhr, DE
• Reinhard Langer · Krefeld, DE

Key dates

• Filing date: Aug 6, 1993
• Grant date: Sep 6, 1994
• Expiry date: Aug 6, 2013

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C68/06
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Diaryl carbonates are prepared from dialkyl carbonates and phenolic compounds by transesterification in the presence of a transesterification catalyst at 60.degree.-320.degree. C. in an apparatus composed of two columns in a continuous procedure. In the first column, the starting materials form essentially the associated alkyl aryl carbonate, from which, in the second column, the diaryl carbonate is produced by further transesterification and disproportionation.