Process for isomerizing monochlorotoluenes or dichlorotoluenes

US4935561A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Klaus Eichler · Laufenburg (Baden), DE
• Hans-Jurgen Arpe
• Herbert Baltes · Losheim, DE
• Ernst I. Leupold · Neu-Anspach, DE

Key dates

• Filing date: May 31, 1985
• Grant date: Jun 19, 1990
• Expiry date: May 31, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/582
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for isomerizing monochlorotoluenes or dichlorotoluenes on a zirconium-containing zeolite catalyst of the Pentasil type. Catalysts of this type are distinguished by a particularly high activity coupled with a long service life. In particular, the invention relates to the preparation of a mixture 3-chlorotoluene and 4-chlorotoluene by isomerizing 2-chlorotoluene on zircoium-containing zeolite catalysts of the Pentasil type. The invention also relates to the preparation of a mixture of 2,5-dichlorotoluene and 3,4-dichlorotoluene by appropriate isomerization of 2,4-dichlorotoluene, and to the preparation of a mixture of 2,4-dichlorotoluene and 2,5-dichlorotoluene by appropriate isomerization of 3,4-dichlorotoluene.