反应详情
EQUATION
反应方程式
REACTANTS
反应物
PRODUCTS
生成物
AUXILIARIES
试剂、催化剂与溶剂
CONDITIONS
反应条件
- 温度
- 0 °C
PROCEDURE
实验过程
To a of solution ethyl 2-(4,4-difluorocyclohexyl)acetate (1.44 g, 7.00 mmol) in anhydrous tetrahydrofuran (23 mL) and anhydrous methanol (0.6 mL) was added lithium borohydride (4 M in tetrahydrofuran, 3.5 mL, 16.00 mmol) at 0° C. and the mixture was heated to reflux for 2 hours. The mixture was then cooled to 0° C. and quenched with methanol until gas evolution ceased. The solution was warmed to ambient temperature then poured into water (50 mL). The aqueous layer was separated and extracted with diethyl ether (3×20 mL). The combined organic layers were washed with brine; dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give the crude alcohol (0.98 g), which was dissolved in anhydrous dimethylsulfoxide (6 mL), tert-butyl 5-chloro-2,4-difluorobenzoate (1.64 g, 6.60 mmol) and cesium carbonate (4.11 g, 12.6 mmol) was added. The reaction mixture was heated at 70° C. for 2 hours and then cooled to ambient temperature and diluted with water (60 mL) and extracted with ethyl acetate (4×20 mL). The combined organic layers were washed with brine; dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography (0% to 10% ethyl acetate in hexanes) to afford the title compound (0.681 g, 29%): 1H NMR (300 MHz, CDCl3) δ 7.88 (d, J=7.7 Hz, 1H), 6.63 (d, J=12.1 Hz, 1H), 4.08 (t, J=6.6 Hz, 2H), 2.17-2.07 (m, 2H), 1.77-1.62 (m, 5H), 1.57 (s, 9H), 1.42-1.29 (m, 4H).
WORKUP
后处理
- temperaturethe mixture was heated
- temperatureto reflux for 2 hours
- customquenched with methanol until gas evolution
- temperatureThe solution was warmed to ambient temperature
- additionthen poured into water (50 mL)
- customThe aqueous layer was separated
- extractionextracted with diethyl ether (3×20 mL)
- washThe combined organic layers were washed with brine
- dry with materialdried over anhydrous sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
- customto give the crude alcohol (0.98 g), which
- temperatureThe reaction mixture was heated at 70° C. for 2 hours
- temperaturecooled to ambient temperature
- extractionextracted with ethyl acetate (4×20 mL)
- washThe combined organic layers were washed with brine
- dry with materialdried over anhydrous sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
- customThe residue was purified by column chromatography (0% to 10% ethyl acetate in hexanes)