A novel method for synthesizing a series of tribromomethylarenes by halogen exchanging of tri-chloromethylarenes with boron tribromide was reported. Mild reaction conditions, high yield and good se-lectivity are most characteristic of this method. The influence factors and the mechanism of the reaction have also been studied. It was found that the reaction was accelerated obviously by the electron-donating substituting groups and decreased by the electron-withdrawing substituting groups and the reaction inhibited greatly when the groups were o-substituting groups. Thirteen compounds have been synthesized including a new compound with this method.

Key words: boron tribromide, trichloromethylarene, tribromomethylarene, displacement reaction, tribromomethylation