DBU (1.7 equiv, 1.16 mL, 7.76 mmol) was added to a solution of 2-bromo-4-fluorobenzoicacid (1.0equiv, 1.0 g, 4.57 mmol) and iodomethane (2.0 equiv, 0.57 mL, 9.14 mmol) in CH3CN(11 mL) at 23 °C. After stirring for 48 h, the reaction was quenched with H2O(10 mL) and extracted with Et2O (2 x 10 mL). The combined organic extracts were washed with water (20 mL) and brine (20 mL), dried over Na2SO4 and filtrated. Evaporation of the solvent under reduced pressure followed by flash chromatography (SiO2, 95/5 hexane/EtOAc) afforded 1.0 g (98%)of Methyl 2-bromo-4-fluorobenzoate as a colourless oil.
