Although occasionally used today as a means of preparing 4-(aryl)-2,2′-bipyridines, the yields are low (usually around 30%) and can be inconsistent. In addition, isolation of the desired product can be difficult when isomers are formed. Alternatively, 4-bromo-2,2′-bipyridine can be functionalized via lithium–halogen exchange or palladium-catalyzed coupling reactions, giving mono-substituted products. The usefulness of this methodology is limited by the availability of the starting ...
![2-[4-(4-bromo-phenyl)-6-ethoxy-5,6-dihydro-4H-pyran-2-yl]-pyridine Structure](https://image.chemsrc.com/caspic/161/477566-82-8.png)
![1-[3-oxo-3-(2-pyridyl)propen-1-yl]-4-bromobenzene Structure](https://image.chemsrc.com/caspic/455/16232-01-2.png)