Synthesis
To a solution of 5-bromo-2-methylpyridine (151; 10 g, 58.1 mmol) in THF (150 mL) was added n-BuLi (2.5 M, 25.6 mL) at -78 ℃. The reaction mixture was stirred at this temperature for Ih. DMF (1.30 mL) was added,, and the resulting reaction mixture was stirred for 1 h at -78 °C. The addition of aq quenched the reaction. NH4Cl. Upon warming to room temperature, the mixture was extracted with EtOAc. The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. The resulting residue was purified by chromatography to afford 6-methylnicotinaldehyde 152 (5.0 g, 72percent).
