PROCESS FOR PREPARING 2,2-,2,4-OR 4,4-BIPYRIDYLS

摘要

1338399 Bipyridyls IMPERIAL CHEMICAL INDUSTRIES Ltd 27 July 1971 [17 Aug 1970] 39481/70 Heading C2C 2,21-, 4,4SP1/SP- or 2,4SP1/SP-Bipyridyls are prepared by heating pyridine or an alkylpyridine which is unsubstituted in the 2- and/or 4-positions of the ring with (a) Cl 2 , Br 2 or I 2 , (b) a 4-bromo-, 4- chloro-, or 4-iodo pyridine or a derivative thereof having one or more alkyl substituents in the ring, or (c) a 1-(4-pyridyl)-pyridinium bromide, chloride or iodide or derivative thereof having one or more alkyl substituents in one or both of the pyridine rings, in the liquid phase at superatmospheric pressure at a temperature of at least 150‹ C.