反应详情

To a slurry of Intermediate 3 (190 mg, 0.5 mmol), (S)-isoxazolidin-4-ol hydrochloride (95 mg, 0.75 mmol) and triethylamine (0.4 mL) in 10 mL of dichloromethane, was added NaBH(OAc)3 (0.32 g, 1.5 mmol) at room temperature. The reaction was stirred for 12 hour at room temperature and then quenched with 1N—NaOH. It was extracted with ethyl acetate and washed twice with brine. The collected organic layer was dried over anhydrous sodium sulfate and then concentrated in vacuo. The resulting residue was purified by silica gel chromatography (DCM/MeOH) to afford desired Compound No. 31 as a pale yellow solid (159 mg, 70%); MS (ESI) m/z 454 [M+H]+. 1H NMR (300 MHz, CDCl3) δ 8.43 (s, 1H), 8.34 (d, J=5.4 Hz, 1H), 7.89 (s, 1H), 7.68 (s, 1H), 7.14-7.16 (m, 3H), 4.73 (brs, 1H), 4.23 (brs, 1H), 3.92-3.96 (m, 2H), 3.84 (brs, 1H), 3.63 (s, 3H), 3.25 (brs, 1H), 2.73 (brs, 1H), 2.40 (s, 3H), 2.36 (s, 3H

1. customquenched with 1N—NaOH
2. extractionIt was extracted with ethyl acetate
3. washwashed twice with brine
4. dry with materialThe collected organic layer was dried over anhydrous sodium sulfate
5. concentrationconcentrated in vacuo
6. customThe resulting residue was purified by silica gel chromatography (DCM/MeOH)