PROCESS FOR THE PREPARATION OF DI- OR TRIFLUOROMETHOXYPHENYL KETONES OR OF DI- OR TRIFLUOROMETHYLTHIOPHENYL KETONES

摘要

A process for the preparation of di- or trifluoromethoxyphenyl ketones or di- or trifluoromethylthiophenyl ketones, characterized in that, in a first stage, a di- or trihalomethoxybenzene or a di- or trihalomethylthiobenzene is reacted with a trihalomethylated aromatic or aliphatic compound in the presence of boron trifluoride in an amount such that the absolute pressure of boron trifluoride within the reaction vessel exceeds 1 bar, and in the presence of hydrofluoric acid as a solvent and in that, in a second stage, the product of the first stage is hydrolyzed. The resultant products are useful as intermediates in the synthesis of compounds having a pharmaceutical or phytosanitary (e.g., herbicidal) activity.