Process for producing 2,6-dichlorobenzonitrile.

摘要

A process for producing 2,6-dichlorobenzonitrile by ammoxidation comprising contacting a starting gas consisting of 2,6-dichlorotoluene, air and ammonia, which comprises carrying out this reaction under the following conditions: (a) the concentration of 2,6-dichlorotoluene in the starting gas is 2.6 mole% or more. (b) the reactor effluent gas is contacting with water to cool to a temperature in the range of 50 DEG to 90 DEG C, whereby 2,6-dichlorobenzonitrile in the reactor effluent gas is collected as a slurry in which solidified 2,6-dichlorobenzonitrile is dispersed in water, and 2,6-dichlorobenzonitrile is obtained from the slurry, and (c) the cooled reactor effluent gas from which 2,6-dichlorobenzonitrile has been removed is contacted with water again to cool to a temperature in the range of 0 DEG to 40 DEG C, whereby unreacted 2,6-dichlorotoluene in the gas is collected as a dispersion in which it is dispersed in water and 2,6-dichlorotoluene is recovered from the dispersion. Also, there is disclosed a process for purifying 2,6-dichlorobenzonitrile obtained by subjecting 2,6-dichlorotoluene to ammoxidation, which comprises subjecting the 2,6-dichlorobenzonitrile to solid-liquid separation procedure in a molten state.