Halogenation of pyridine 1‐oxides

Abstract

Abstract The chlorination and bromination of α‐lithiopyridine 1‐oxides has been studied. Only dihalogenated pyridine 1‐oxides are formed. In the case of bromination dipyridyl derivatives are also formed, and, indeed, predominate. Chloromercuration of the lithiopyridine 1‐oxides gave highly insoluble, unresolvable mixtures of pyridylmercury derivatives. These could be brominated readily to give mixtures of 2‐bromo‐ and 2,6‐dibromopyridine 1‐oxides.