反应详情

温度

0 °C

Methyl magnesium bromide (3.0M solution in diethyl ether, 4.3 ml, 12.9 mmol) was added to a stirred solution of tert-butyl (1S)-2-[methoxy(methyl)amino]-1-methyl-2-oxoethylcarbamate (Tetrahedron: Asymmetry 1996, 7, 985) (1 g, 4.3 mmol) in anhydrous tetrahydrofuran (20 ml) at −60° C. under a nitrogen atmosphere. The mixture was allowed to warm to 0° C. and to then room temperature and was stirred at room temperature for 1 hour. Aqueous saturated ammonium chloride was added and aqueous phase was extracted with diethyl ether (2×76 ml). The combined organic extracts were then washed with saturated aqueous ammonium chloride solution and brine. The organic phase was then dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with a solvent gradient of dichloromethane:methanol (99:1 to 98:2), to afford the title compound as a colorless solid, 412 mg, 51% yield.

1. extractionaqueous phase was extracted with diethyl ether (2×76 ml)
2. washThe combined organic extracts were then washed with saturated aqueous ammonium chloride solution and brine
3. dry with materialThe organic phase was then dried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by column chromatography on silica gel
7. washeluting with a solvent gradient of dichloromethane:methanol (99:1 to 98:2)