Process for the continuous preparation of aryl carbonates

US5523451A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Johann Rechner · Krefeld, DE
• Norbert Schon · Krefeld, DE
• Paul Wagner · Mülheim an der Ruhr, DE
• Hans-Josef Buysch · Krefeld, DE
• Stephan Kabelac · Langenfeld, DE

Key dates

• Filing date: Mar 4, 1994
• Grant date: Jun 4, 1996
• Expiry date: Mar 4, 2014

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J2219/00182
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Organic carbonates which contain at least one aromatic ester group can be obtained continuously from carbonates, which contain at least one aliphatic ester group, and a phenolic compound in the presence of a transesterification catalyst known per se in that the reaction is carried out in a bubble column reactor or in a cascade of at least two bubble column reactors in such a way that the phenolic compound is metered into the first bubble column and the carbonate containing at least one aliphatic ester group is metered into each individual bubble column, but preferably only into the last bubble column. The carbonate containing at least one aromatic ester group is taken off in the liquid state from the last bubble column. Volatile reaction products, for example eliminated alcohol or a dialkyl carbonate are taken off at the upper end of each individual bubble column, preferably at the upper end of the first bubble column.