D 2543 (OTTO) 2,6-Dibromopyridine, 98% Cas 626-05-1 - used as a tridentate chelating ligand and in the formation of macrocycles containing the terpyridine moiety. D 2543 (OTTO) 2,6-Dibromopyridine, 98% Cas 626-05-1 - used to produce 6-bromo-2-methoxypyridine.