General procedure for the synthesis of 2-bromo-6-(bromomethyl)naphthalene from 6-bromo-2-(hydroxymethyl)naphthalene: To a solution of (6-bromonaphthalen-2-yl)methanol (1.19 g, 5 mmol) in anhydrous ethyl ether (40 mL) was added phosphorus tribromide (PBr3, 1.52 g, 22 mmol) dropwise at 0 °C. The reaction mixture was stirred at room temperature for 3 hours. After the reaction was completed, the reaction mixture was neutralized with aqueous sodium bicarbonate (NaHCO3). The product was extracted with ether (40 mL x 2), the organic layers were combined and dried with anhydrous sodium sulfate (Na2SO4). After filtration, the organic phase was concentrated to obtain the crude product. Finally, the crude product was purified by fast silica gel column chromatography (eluent: petroleum ether) to afford the target compound 2-bromo-6-(bromomethyl)naphthalene (1d, 1.27 g, 85% yield) as a white solid.
