Nickel catalyst, Raney, in preparation of 2,2 -bipyridine

Nickel catalyst, Raney, in preparation of 2,2 -bipyridine, 46, S W7-J, preparation of, 46, S Nickel ion, as catalyst for decomposition of diazonium xanthates, 47, 107... 

This procedure serves two purposes. It provides a synthesis for the important chelating reagent 2,2 -bipyridine, a substance of interest in several fields of chemistry, and it gives a preparation of an active, degassed Raney nickel catalyst. 

In 1956 it was found that when pyridine is refluxed with a modified Raney-nickel catalyst, 2,2 -bipyridine (1) is formed in satisfactory yield. The isomeric bipyridines could not be detected, and the product was readily purified. Similar heterocyclic biaryls have been formed in the same way from substituted pyridines and from some related compounds, the yield being dependent on the nature of the compound. The reaction has become the method of choice for the preparation of 2,2 -bipyridine, and it is now used on an industrial scale. Bipyridyls are of particular importance as chelating agents. 

---