PROCESS FOR ISOMERIZING MONOCHLOROTOLUENES OR DICHLOROTOLUENES

摘要

The invention relates to a process for isomerizing monochlorotoluenes or dichlorotoluenes on a zirconiumcontaining 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 of 3-chlorotoluene and 4-chlorotoluene by isomerizing 2-chlorotoluene on zirconium-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.