General procedure for the synthesis of 2-(benzyloxy)-4-bromo-1-fluorobenzene from benzyl bromide and 5-bromo-2-fluorophenol: To a solution of acetone (10 ml) containing the product of step a) (0.802 g, 4.20 mmol) and benzyl bromide (0.755 ml, 6.30 mmol) was added potassium carbonate (1.16 g, 8.40 mmol). The mixture was heated at reflux at 60°C for 16 hours. After completion of the reaction, the solid was removed by filtration and washed with acetone. The filtrate was evaporated to give the crude product. The residue was purified by fast chromatography using 0-20% ethyl acetate/isohexane as eluent, resulting in 1.04 g (88% yield) of 2-(benzyloxy)-4-bromo-1-fluorobenzene as an oil, which crystallized on cooling. The NMR hydrogen spectrum (400 MHz, CDCl3) data were as follows: δ 5.08 (2H, s), 6.98 (2H, m), 7.13 (1H, dd, J=7.4,2.2Hz), 7.37 (5H, m).
