反应详情

Under nitrogen, 6.3 mL (15.8 mmol) of n-BuLi (2.5M in hexanes) was added to a stirred solution of 3.9 g (13.2 mmol) of 5-bromo-6-(4-fluorophenyl)-1,3-benzodioxole (Step 1) in 30 mL of anhydrous THF at -78° C. After 30 minutes, 4.5 mL (39.4 mmol) of trimethylborate was added. The reaction was warmed to ambient temperature and stirred for 3 hours prior to the addition of 60 mL of 5% NaOH. The reaction was stirred for an additional 60 minutes, the THF removed in vacuo, and the pH adjusted to ca. 4. The residue was dissolved in ethyl acetate; the resulting solution was dried over Na2S04 and concentrated in vacuo to give 1.7 g (50%) of [6 (4-fluorophenyl)-1,3-benzodioxol-5-yl] boronic acid as a pale yellow solid: NMR (CDCl3) δ 4.00 (br s, 2H), 6.06 (s, 2H), 6.75 (s, 1H), 7.08-7.17 (m, 2H), 7.26 (s, 1H), 7.31-7.39 (m, 2H).

1. stirringThe reaction was stirred for an additional 60 minutes
2. customthe THF removed in vacuo
3. dissolutionThe residue was dissolved in ethyl acetate
4. customthe resulting solution was dried over Na2S04
5. concentrationconcentrated in vacuo