Process for producing 2,5-dichloro-p-xylene

A process for producing dichlorinated p-xylene having a high ratio of 2,5-dichloro-p-xylene to 2,3-dichloro-p-xylene isomers which comprises reacting 2-chloro-p-xylene and anhydrous ferric chloride at a temperature of from 25.degree. C. to 150.degree. C. and wherein said reaction is carried out with the reactants in contact with a catalytically effective amount of catalyst chosen from the group consisting of antimony halides, aluminum halides and combinations of antimony halides and aluminum halides with organic sulfur compounds characterized by the presence of divalent sulfur.