A concise synthesis of 2,4-disubstituted pyridines: A convenient synthesis of 2-bromo-4-iodopyridine via halogen dance and its successive one-pot disubstitutions

As a key building block for 2,4-disubstituted pyridines, 2-bromo-4-iodopyridine was synthesized conveniently from 2-bromopyridine using LDA and I-2 via 'halogen dance'. 2-Bromo-4-iodopyridine was then converted to other 2,4-diaryl pyridines and 4-aryl-2,2'-bipyridines in one-pot reactions.