| 摘要 |
<p>Bipyridyls are manufactured by interacting an alkali metal or an alkaline earth metal with pyridine or an alkyl pyridine in the presence of an oxidizing agent. The preferred metal is magnesium and the metal may be used in the pure form or as an alloy. Suitable oxidizing agents include oxygen and gaseous mixtures containing oxygen such as air, and also organic nitro compounds, e.g. nitrobenzene and nitroalkanes. In the case of magnesium it is desirable to use a small amount of an alkali metal, a halogen, an alkyl halide or a quaternary pyridinium salt as initiator. In general a mixture of 2,21-, 2,41- and 4,41-isomers are obtained. The bipyridyls may be isolated from the reaction mixtures by fractional distillation (particularly under reduced pressure), fractional crystallization, solvent extraction or by a combination of these methods.</p> |
