It is a colourless liquid although older samples can appear yellow.
Bromobenzene is prepared by the action of bromine on benzene in the presence of Lewis acid catalysts such as aluminium chloride or ferric bromide.
[3] Bromobenzene is used to introduce a phenyl group into other compounds.
One method involves its conversion to the Grignard reagent, phenylmagnesium bromide.
This reagent can be used, e.g. in the reaction with carbon dioxide to prepare benzoic acid.