| 摘要 |
<p>Terpyridyl impurity is removed from a bipyridyl by contacting the impure bipyridyl with a substantially water-immiscible organic solvent and an aqueous acid medium containing at least one compound of nickel, cobalt, zinc or iron and thereafter separating the organic solvent phase which contains the pipyridyl. The starting impure bipyridyls may be obtained from a magnesium-pyridine interaction product, e.g. by oxidation. The substantially water-immiscible organic solvent may be, for example, toluene, benzene, trichloroethylene or perchloroethylene. The aqueous acid medium preferably has a pH value of 5-6 and suitable acids are, for example, hydrochlori and sulphuric acids. In order to maintain the mixture at the required pH it may be necessary to add buffers or alkali. Preferably, the purification is carried out at a temperature of not less than 60 DEG C. and surface-active agents may be added to the mixture to promote initimate contact of the two liquid phases.</p> |
