Process for the preparation of 2,4-dichloro-5-fluorobenzonitrile and 2,6- dichloro-3-fluorobenzonitrile

摘要

A mixture of 2,4-dichloro-5-fluorotoluene and 2,6-dichloro-3- fluorotoluene which cannot be separated in an economically efficient manner and can be reacted individually to give the corresponding benzonitriles is subjected according to the invention to ammoxidation in the form of this mixture and then separated at the stage of the benzonitriles by methods known to the person skilled in the art.