反应详情

To a solution of 2-hydroxy-4-(2-hydroxy-ethoxy)-benzoic acid methyl ester (3.025 g, 14.25 mmol) in methylene chloride (80 mL) was added carbon tetrabromide (6.216 g, 18.74 mmol) and triphenylphosphine (5.012 g, 19.10 mmol). The reaction was stirred 3 hours at room temperature then additional carbon tetrabromide (1.967 g, 5.931 mmol) and triphenylphosphine (1.568 g, 5.97 mmol) was added and stirring continued overnight. The reaction mixture was concentrated in vacuo and the residue was purified by flash chromatography using ethyl acetate/hexanes (10/90 to 20/80) to afford 4-(2-bromo-ethoxy)-2-hydroxy-benzoic acid methyl ester (3.070 g, 78%) as a white solid. 1H NMR (300 MHz, CDCl3); δ 11.00 (s, 1H), 7.76 (d, 2H), 6.46 (m, 2H), 4.32 (t, 2H), 3.93 (s, 3H), 3.65 (t, 2H).

1. stirringstirring continued overnight
2. concentrationThe reaction mixture was concentrated in vacuo
3. customthe residue was purified by flash chromatography