反应详情

To ethyl 3-(benzyl(cyclohexyl)amino)-2-hydroxy-2-methylpropanoate (7 g, 21.9 mmol) in 50 ml of dichlormethane at −78° C., was added DAST (4.3 ml, 32.8 mmol) dropwise. The reaction mixture was gradually warmed up to room temperature and stirred for 2 h. It was then diluted to dichloromethane, washed by NaHCO3, brine and water. Organic extract dried and concentrated to a residue, which was purified on silica gel column chromatographically (Hex/EtOAc=40:1 to 20:1) to give 6.8 g product (97%) as light yellow liquid. [M+H] calc'd for C19H28FNO2, 322. found 322.

1. washwashed by NaHCO3, brine and water
2. extractionOrganic extract
3. customdried
4. concentrationconcentrated to a residue, which
5. customwas purified on silica gel column chromatographically (Hex/EtOAc=40:1 to 20:1)