Patent ID: 6222079
Filing Date: 2001-04-24
Classification: C07C

Abstract:
In a method of chlorinating a substituted benzene having the general formula ##STR2##using a Friedel-Crafts catalyst and a chlorinating agent, the improvement comprising chlorinating using about 0.3 to about 1.5 equivalents of a chlorinating agent per equivalent of said substituted benzene in the presence of about 0.001 to about 5 wt % of a cocatalyst selected from the group consisting of thianthrene and thianthrene derivatives, whereby the percentage of the 2,5-isomer is increased when said substituted benzene is ortho or meta-substituted, the percentage of the 3,4-isomer is increased when said substituted benzene is para-substituted, and the percentage of the 2,4,5-isomer is increased when said substituted benzene is 2,4-disubstituted, 3,4-disubstituted, or 2,5-disubstituted, where R is alkyl from C.sub.1 to C.sub.4 and X is halogen.