Halex process

[1] The reaction conditions call for hot (150-250 °C) solution of the aryl chloride and anhydrous potassium fluoride.

The reaction is mainly applied to nitro-substituted aryl chlorides.

[2] The following reactions are practiced commercially in this manner:[3] The nitro groups in the above compounds can be reduced to give the corresponding aniline.

Thus, the Halex method provides access to a host of fluoroanilines.

For producing aryl fluorides, the Halex process is complementary to the Balz-Schiemann reaction and its variants.