反应详情

温度

-78 °C

To a solution of ethyl 3-(6-fluoro-5-nitro-1H-indol-2-yl)-3-methylbutanoate (34 g, 0.11 mol) in dry CH2Cl2 (400 mL) was added drop-wise DIBAL-H (283.4 mL, 0.27 mol) over 2 hours at −78° C. The reaction mixture was stirred for 10 hours at −78° C. and then quenched by adding water (200 mL). The precipitate was filtered off and washed with methanol. The filtrate was extracted with CH2Cl2 (200 mL×3), the combined organic layers were washed with brine, dried over anhydrous Na2SO4 and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (petroleum ether/ethyl acetate 50:1) to give 3-(6-fluoro-5-nitro-1H-indol-2-yl)-3-methylbutan-1-ol (6.6 g, 22%). 1H NMR (400 MHz, CDCl3) δ 9.35 (brs, 1H), 8.30 (d, J=7.6 Hz, 1H), 7.11 (d, J=12.0 Hz, 1H), 6.35 (d, J=1.2 Hz, 1H), 3.74 (t, J=6.4 Hz, 2H), 1.9 (t, J=6.4 Hz, 2H), 1.4 (s, 6H).

1. customquenched
2. additionby adding water (200 mL)
3. filtrationThe precipitate was filtered off
4. washwashed with methanol
5. extractionThe filtrate was extracted with CH2Cl2 (200 mL×3)
6. washthe combined organic layers were washed with brine
7. dry with materialdried over anhydrous Na2SO4
8. concentrationconcentrated under reduced pressure
9. customThe residue was purified by column chromatography on silica gel (petroleum ether/ethyl acetate 50:1)