Polyhalogenoaromatic compounds. Part XXIII. Synthesis and reactions of heptachloro-3-lithio-4,4′-bipyridyl
Abstract
Metal–halogen exchange between n-butyl-lithium and octachloro-4,4′-bipyridyl gave heptachloro-3-lithio-4,4′-bipyridyl, whereas nucleophilic substitution of the bipyridyl by piperidine took place at the 2- and 2′-positions. The reactions of the 3-lithio-compound with water, dimethyl sulphate, and aromatic nitriles gave the expected products. On heating in the presence of p-di-isopropylbenzene the 3-lithio-compound gave an adduct of 5,6-dichloro-4-(tetrachloro-4-pyridyl)-2-pyridyne.