反应详情

tert-butyldimethylchlorosilane (6.51 g, 43.2 mmol) was added to a solution of (+/−)(3R,4R)-benzyl 4-((tert-butoxycarbonyl)amino)-3-hydroxypiperidine-1-carboxylate (prepared according to a published literature procedure: Fink, Brian, et al., WO 2005/066176, 10.1 g, 28.8 mmol) and imidazole (3.92 g, 57.6 mmol) in DMF (60 mL). The mixture was stirred at room temperature overnight. Ice water was added and the reaction mixture was extracted with ether twice, the combined extracts were washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuo, the crude product was purified by flash chromatography on silica gel using an automated ISCO system (330 g column, eluting with 5-20% ethyl acetate/dichloromethane) to give (+/−)-(3R,4R)-benzyl 4-((tert-butoxycarbonyl)amino)-3-((tert-butyldimethylsilyl)oxy)piperidine-1-carboxylate (13.3 g) as a white solid.

1. customprepared
2. extractionthe reaction mixture was extracted with ether twice
3. washthe combined extracts were washed with brine
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customthe crude product was purified by flash chromatography on silica gel using
8. washan automated ISCO system (330 g column, eluting with 5-20% ethyl acetate/dichloromethane)