Diethyl Ether → 5-Bromo-4-methylpyridine-3-carbaldehyde

2,6-Dibromotoluene (9.8 g, 39 mmol) in THF (300 mL) was stirred under N2 and was then cooled to −100° C. (ether/liquid N2). n-BuLi (16.4 mL, 41 mmol, 2.5 M in hexane) was then added drop wise and after stirring for 5 minutes DMF (4.5 mL, 58.6 mmol) was added. The reaction was stirred for a further 20 minutes and then for an hour at −78° C. The reaction was quenched with saturated aqueous NH4Cl and allowed to warm up to room temperature. The reaction was diluted with water and the pH adjusted to pH 7-8 with sat. aqueous NaHCO3. The mixture was evaporated in vacuo to remove the THF, and the product was then extracted with Et2O (×3). The combined organic layers were washed with brine and dried (MgSO4). The product was filtered and evaporated on vacuo to give 5-bromo-4-methyl-pyridine-3-carbaldehyde as a colourless solid which was used without further purification.