反应详情

温度

90 °C

To a solution of (6-bromo-1,8-diethyl-1,3,4,9-tetrahydro-pyrano[3,4-b]indol-1-yl)-acetic acid ethyl ester (5.2 g, 13.2 mmol) in tetrahydrofuran at room temperature under nitrogen was dropped a 2.0 M solution of lithium borohydride in tetrahydrofuran. The reaction mixture was heated at 90° C. (oil bath) for 5 hours. After cooling to room temperature, it was quenched with 5% hydrochloric acid solution until the excess lithium borohydride was destroyed. Water was added and the mixture extracted with ethyl acetate. Extracts were dried over magnesium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel, 50% ethyl acetate/hexane) to give the title compound (3.80 g, 82% yield). 1H NMR (CDCl3) δ 8.07 (s, 1H), 7.64 (d, 1H), 7.26 (d, 1H), 4.17 (m, 2H), 3.86 (m, 2H), 2.94 (m, 3H), 2.87 (dt, 1H), 2.76 (t, br, 1H), 2.36 (m, 1H), 2.24 (m, 1H), 2.13 (m, 2H), 1.49 (t, 3H), 1.08 (t, 3H). ES-MS (m/z) 352 [M+1]+, 350 [M−1]−.

1. temperatureAfter cooling to room temperature
2. customit was quenched with 5% hydrochloric acid solution until the excess lithium borohydride
3. customwas destroyed
4. additionWater was added
5. extractionthe mixture extracted with ethyl acetate
6. dry with materialExtracts were dried over magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe crude product was purified by column chromatography (silica gel, 50% ethyl acetate/hexane)