反应详情

To a solution of triphenyl phosphine (7.7 g, 29 mmol), in tetrahydrofuran (40 mL), diethylazodicarboxylate (5.12 g, 29 mmol) was added and the solution was stirred for 20 minutes. 4-Fluorophenol (3 g, 27 mmol) was added and the mixture was stirred for another 20 minutes at 0° C. N—Boc-4-hydroxypiperidine (5.9 g, 29 mmol) was added dissolved in tetrahydrofuran (20 mL) and the mixture was stirred at room temperature overnight. Water was added and the solution was extracted three times with dichloromethane. The combined organic layers were washed with water and brine, dried over magnesium sulfate, filtered and evaporated. The crude product was purified by flash-chromatography on silica gel with hexane:ethyl acetate (1:0 to 1:1) to give 4.8 g (60%) of the product as a white solid. MS (m/e): 296.3 (M−H+).

1. stirringthe mixture was stirred for another 20 minutes at 0° C
2. stirringthe mixture was stirred at room temperature overnight
3. extractionthe solution was extracted three times with dichloromethane
4. washThe combined organic layers were washed with water and brine
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. customevaporated
8. customThe crude product was purified by flash-chromatography on silica gel with hexane:ethyl acetate (1:0 to 1:1)