Preparation of 1,4-dichlorobenzene

Abstract

1,2-dichlorobenzene is isomerized to 1,4-dichlorobenzene in the presence of a catalyst comprising (a) at least one of AlCl.sub.3 and AlBr.sub.3 and (b) at least one of iodine, alkaline earth metal halides and sulfates and lanthanide halides. Benzene and/or dichlorobenzene is chlorinated with free chlorine in the presence of a catalyst composition comprising (a) at least one suitable metal halide (preferably AlCl.sub.3, SbCl.sub.5 or FeCl.sub.3) and (b) free iodine and/or at least one organic iodo-compound (preferably methyl iodide or p-iodochlorobenzene), so as to obtain a reaction product comprising 1,4-dichlorobenzene). A preferred catalyst composition comprises (a) at least one of AlCl.sub.3 and AlBr.sub.3, (b) free iodine and (c) at least one of alkaline earth metal halides, alkaline earth metal sulfates and lanthanide halides.

Dependencies are inferred from the claim text.