1,3-dibromo-5,5-dimethylhydantoin (DBDMH) is a useful and easy to handle reagent for bromination of various aromatic derivatives substituted with electron donating groups. In the presence of trimethylsilyltrifluoromethanesulfonate, DBDMH showed increased reactivity, and in one case, the reaction followed another pathway, suggesting an alternative mechanism. (C) 1997 Elsevier Science Ltd.