[Synthesis]
Step D: A solution of tributylammonium tetrabromide (11.8 g, 24.4 mmol) in dichloromethane (80 mL) was slowly added dropwise to a mixture of dichloromethane (20 mL) and methanol (20 mL) of the product obtained in Step C (5.0 g, 22.2 mmol) at room temperature for a controlled period of more than 1 hour. After the dropwise addition, the reaction mixture was continued to be stirred at room temperature for 15 hours. After completion of the reaction, the mixture was concentrated. The concentrated residue was dissolved in dichloromethane and washed three times with saturated sodium bicarbonate solution. The organic layer was separated and concentrated and the residue was dissolved in dimethylformamide (100 mL). Subsequently, lithium carbonate (5.3 g, 71.1 mmol) and lithium bromide (4.1 g, 46.6 mmol) were added to the solution, and the reaction mixture was stirred at 140 °C for 1.5 hours. At the end of the reaction, it was cooled to room temperature, the solid was collected by filtration and washed with ethyl acetate. The filtrates were combined, washed four times with water and dried over anhydrous sodium sulfate to give the final 7-bromonaphthalen-1-ol (2.7 g, 56% yield). The product was characterized by 1H NMR (300 MHz, CDCl3): δ 8.41 (d, J = 1.8 Hz, 1H), 7.68 (d, J = 8.7 Hz, 1H), 7.57 (dd, J = 8.7, 1.8 Hz, 1H), 7.41 (d, J = 8.4 Hz, 1H), 7.28-7.35 (m, 1H), 6.62 (d J = 7.2 Hz, 1H), 5.80 (br s, 1H). |