In strongly acidic medium , aniline is protonated as anilinium ion which is meta directing so it gives meta product also .
( d ) Aniline does not undergo Friedel-Crafts reaction due to salt formation with aluminium chloride , the Lewis acid , which is used as a catalyst . Due to this , nitrogen of aniline acquires positive charge and hence . behave like a strong deactivating group for further chemical reaction .