Ionic liquid promoted regioselective monobromination of aromatic substrates with N-bromosuccinimide

Abstract Aromatic substrates were monobrominated regioselectively with NBS in the ionic liquid 1,3-di- n -butylimidazolium tetrafluoroborate [bbim]BF 4 in 5 min at 28°C in excellent isolated yields (80–98%) in the absence of a catalyst.