Synthesis
2,6-Dibromo-4-methylpyridine was prepared as follows: The specific steps were as follows: ⁸-hydroxy-methyl-oxo-dihydro-S-pyridinecarboxynitrile hydrochloride (D1, 5 g, 30.94 mmol) and phosphorus oxybromide (25 g, 87.2 mmol) were heated together at 13 °C for 6 hours. The mixture was cooled on ice, and water was carefully added. The mixture was then alkalized with 2 M sodium hydroxide solution and extracted with dichloromethane. The organic phase was separated and evaporated to give a light brown solid. It was purified by silica gel chromatography (CombiFlashCompanion, Redisep 80 g silica gel column), eluting with a cyclohexane-dichloromethane mixture (100% - 70% cyclohexane). The fractions containing the major components were combined and evaporated to give the title compound (1.279 g, 16%) as a colorless solid.
