Aryne chemistry. Part XIII. Polychloroaromatic compounds. Part III. The generation and reactions of trichloropyridynes

Abstract

Trichloro-3-pyridyne was generated by the elimination of lithium chloride from tetrachloro-4-pyridyl-lithium, and trapped in the form of 1,4-adducts with benzene, p-xylene, p-di-isopropylbenzene, mesitylene, and 1,2,4,5-tetramethylbenzene. Polar and steric factors affecting the addition reactions are discussed. The action of furan on tetrachloro-4-pyridyl-lithium gave polychlorobipyridyls, but with 1,3-diphenylisobenzofuran, the expected adduct was obtained.

A mixture containing two isomeric adducts of trichloro-2-pyridyne was obtained when n-butyl-lithium and pentachloropyridine were heated in the presence of mesitylene.