2216-69-5

5467-58-3

The general procedure for the synthesis of 1-bromo-4-methoxynaphthalene from 1-methoxynaphthalene was as follows: 1-methoxy-3,5-dimethylbenzene (100 mg, 0.73 mmol), N-bromosuccinimide (NBS, 260 mg, 1.46 mmol), and a stainless steel ball (5 mm in diameter) were placed in a 10 mL stainless steel milling jar. The ball milling reaction was carried out and the progress of the reaction was monitored by thin layer chromatography (TLC) and proton nuclear magnetic resonance (1H NMR). Upon completion of the reaction, the reaction mixture was transferred to 30 mL of ethyl acetate and cooled at 0 °C. The product was separated as a filtrate by filtration through filter paper and the spent succinimide was separated as a precipitate. The resulting filtrate was concentrated under vacuum to give 250 mg (yield: 85%) of 1-bromo-4-methoxynaphthalene as a colorless powder. To test the efficiency of the large-scale reaction, monobromination of 1-methoxy-3,5-dimethylbenzene on a scale of 1.3 g was also carried out with a reaction time of 1 h. The product was isolated in 87% yield. During the reaction, the grinding equipment was suspended and a small sample was removed from the reaction tank for TLC and 1H NMR analysis. Subsequently, the reaction was restarted and the time of this operation was not included in the total reaction time.