Synthesis of compound 172 (3-benzyloxybenzyl bromide): 3-benzyloxybenzyl alcohol (3.0 g, 14.0 mmol) was dissolved in anhydrous ethyl ether (50 mL) under nitrogen protection and cooled in an ice bath to 0°C. Subsequently, phosphorus tribromide (0.66 mL, 7.0 mmol) was added dropwise (0.66 mL, 7.0 mmol), and after completion of the dropwise addition the ice bath was removed, and the mixture was gradually allowed to come to room temperature and stirred for 3 hours. The reaction mixture was gradually warmed to room temperature and stirred for 3 hours. After the reaction was completed, the mixture was diluted with ether (60 mL) and washed with deionized water (2 × 40 mL), saturated sodium bicarbonate solution (2 × 40 mL) and saturated saline (2 × 40 mL). The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to remove the solvent to give 3-benzyloxybenzyl bromide (3.76 g, 97% yield) as a light yellow solid.
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