2-Bromo-1-methylpyridinium iodide

synthetischeThe title reagent (1a) as well as the chloro analog (1b) can be prepared by adding 1.2 equiv of MeI to an acetone solution of 2-bromo- or 2-chloropyridine at 0 °C. After stirring for 3 days at rt the precipitated pyridinium salt is filtered off and washed with dry ether. Further drying under vacuum results in 80-90% yield of the pyridinium salt as a colorless solid which may be used without further purification.