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

摘要

Prepn. of 2,4-dichloro-5-fluorobenzonitrile and 2,6-dichloro-3-fluorobenzonitrile comprises reaction of a mixt. of 2,4-dichloro-5-fluorotoluene and 2,6-dichloro-3-fluorotoluene with ammonia, air and steam at a molar ratio dichlorofluorotoluene:ammonia:air:steam of 1:1-3:7.5-15:0-10. Reaction is carried out in the gas phase at 350-550 degrees C in the presence of a catalyst. Final treatment of the nitrile mixture is by the known Fachmann method.