Ethylation means introduction of an ethyl group in the benzene ring. This is usually carried out by Friedel-Crafts reaction of benzene with ethyl halide (chloride or bromide ) , ethene or ethanol. The Lewis acid catalysts other than anhydrous `AlCl_3` used in this reaction are : anhydrous `FeCl_3,SnCl_4, BF_3` etc.
