Trichloromethylation reaction of aromatic carboxylic acids or aroylchlorides has been accomplished by using tetrachlorophenylphosphine or dichlorophenylphosphine/phosphoric chloride as the transforming agent. The trichloromethylation reaction can be well controlled and the phenylphosphonic dichloride produced in the process can be reclaimed for reuse. A series of trichloromethylated aromatics including two new compounds, such as 3-trichloromethylbromobenzene and 2-trichloromethylmethbenzenetoluene, have been synthesized. The influences and the mechanism of the reaction have also been studied. It was found that the reaction was accelerated obviously with the electron-pushing groups attached to dichlorophenylphosphine and was decreased with the electron-withdrawing groups attached. On the other hand, the effects of substituents of the aromatic acids (or aroylchloride) on the reaction were opposed.

Key words: phenylphosphonicdichloride, conversion of arometic acid, trichloromethylation reaction, trichloromethylated aromatics, tetrachlorophenylphosphine