Process for the isomerisation of dichlorotoluenes

摘要

The invention relates to a process for the isomerisation of dichlorotoluenes on a zirconium-containing zeolite catalyst of the pentasil type. Catalysts of this type are distinguished by high activities and long service life. The invention relates in particular to the preparation of a mixture of 2,5- and 3,4- dichlorotoluene by isomerisation of 2,4-dichlorotoluene, and to the preparation of a mixture of 2,4- and 2,5-dichlorotoluene by isomerisation of 3,4-dichlorotoluene.