| 摘要 |
A method for preparing isomerically pure 2,5-dichlorobenzophenones in good to high yields is provided. The invention comprises Friedel-Crafts aroylation of 1,4-dichlorobenzene using an aroyl halide or aromatic anhydride and at least one Lewis acid, the latter being present in an amount of at least about 1.1 mole per mole of aroyl halide or aromatic anhydride, preferably about 1.5 moles per mole of aroyl halide or aromatic anhydride and, more preferably, from about 2 to about 2.5 moles of Lewis acid per mole of aroyl halide or aromatic anhydride. Preferably, the molar ratio of 1,4-dichlorobenzene to aroyl halide ranges from about 1.2:1 to about 8:1.
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