General procedure for the synthesis of methyl 3-(bromomethyl)pyridine-2-carboxylate from methyl 3-methylpyridine-2-carboxylate: methyl 3-methylpyridine-2-carboxylate (4.1 g, 27.1 mmol), N-bromosuccinimide (NBS, 5.8 g, 32.5 mmol) and azobisisobutyronitrile (AIBN, 100 mg, 0.61 mmol) were dissolved in carbon tetrachloride (55 mL). The reaction mixture was stirred at 90 °C for 16 h under nitrogen protection. After completion of the reaction, the mixture was filtered and the filtrate was concentrated. The concentrate was purified by column chromatography to afford the target product methyl 3-(bromomethyl)pyridine-2-carboxylate (5.0 g, 80.6% yield). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 8.67 (dd, J = 1.6, 4.6 Hz, 1H), 7.91 (dd, J = 1.5, 7.9 Hz, 1H), 7.48 (dd, J = 4.6, 7.9 Hz, 1H), 4.95 (s, 2H), 4.07-4.03 (m, 3H). lCMS ( m/z): 229.9 ([M + H]+).
