I recently did an organic chem lab in which we brominated acetanilide. Now the benzene group had an acetamido group attached to it, which is less powerful activator than an amide (NH2) group but still directs to the ortho and para positions. I can understand that due to steric hindrance, addition in the ortho position would be minimal if not at all. But why is it still that we never used the lewis catalyst during the reaction? could high concentrations of a halogen still cause good yields for halogenation or is there another reason a Lewis acid is not needed? Thanks for any help.