Methanol → Methyl 8-bromoquinoline-2-carboxylate

A suspension of 8-bromoquinoline-2-carboxylic acid (Princeton Biomolecular Research, Monmouth Junction, N.J.; 2.65 g, 10.51 mmol) in DCM (25 mL) at 0° C. was treated with oxalyl chloride, 2.0 M solution in DCM (10.51 mL, 21.0 mmol), followed by 12 drops of DMF. The ice bath was removed, the mixture was stirred at RT for 1 h, becoming completely soluble during that time. The reaction mixture was then concentrated in vacuo and the residue was dissolved in DCM (50 mL) and cooled to 0° C. MeOH (1.7 mL, 42.1 mmol) and TEA (1.7 mL, 12.6 mmol) were added, the ice bath was removed, and the mixture was stirred at RT for 1 h. The reaction mixture was then diluted with DCM (50 mL), washed sequentially with 0.5 N HCl (25 mL), water (25 mL), 0.5 N NaOH (25 mL) and brine (25 mL), then dried over MgSO4, filtered, and concentrated to give methyl 8-bromoquinoline-2-carboxylate as a brown oil. This material was used without further purification, assuming the theoretical yield: 1H NMR (400 MHz, DMSO-d6) δ ppm 8.63 (d, J=8.4 Hz, 1H), 8.24 (d, J=7.4 Hz, 1H), 8.18 (d, J=8.4 Hz, 1H), 8.11 (d, J=8.2 Hz, 1H), 7.64 (t, J=7.8 Hz, 1H), 3.98 (s, 3H). m/z (ESI, +ve ion) 266.0/268.0 (M+H)+.