22061-78-5

2835-97-4

22061-78-5

Step 1: 2-Amino-3-methylphenol (8a, 5.7 g, 46.3 mmol) was dissolved in a solvent mixture of water (30 mL) and 1,4-dioxane (15 mL). The reaction mixture was heated to reflux followed by slow dropwise addition of hydrobromic acid (48%, 17 mL, 0.31 mol) over 20 min. After the dropwise addition was completed, the reaction was continued at reflux for 15 min. The reaction solution was cooled to 0 °C and an aqueous solution of sodium nitrite (20 mL) was added over 30 min. Stirring was continued at 0 °C for 15 min, after which the reaction mixture was poured at once into a mixture of water (20 mL) and hydrobromic acid (48%, 17 mL, 0.31 mol) of cuprous bromide (I) (7.64 g, 53.2 mmol) that had been pre-cooled to 0 °C and treated to avoid light. After stirring at 0 °C for 15 min, the reaction solution was slowly warmed to 60 °C and stirring was continued for 15 min. It was then cooled to room temperature and stirred overnight. Upon completion of the reaction, the mixture was transferred to a partition funnel and extracted with ethyl acetate (3×). The organic phases were combined, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered and concentrated to give the crude product. Purification by CombiFlash fast chromatography system (eluent: 20% ethyl acetate/hexane) gave the target product 2-bromo-3-methylphenol (8b, 1.46 g, 17% yield) as a reddish brown oil.