The reaction of 3-methylimidazo [1, 2-a] pyridine with NBS was reinvestigated and is shown to give products formed by apparent nucleophilic substitution at the 2-position. NBS in CHCIB gave compounds 4 and 6, while NBS in CCl, or Br2 in CHC13 gave exclusively 4. Mechanisms and differences in product formation are discussed; evidence that the previously reported NBS product was in fact 3-bromo-5-methylimidazo [ 1, 2-a] pyridine, ...