(Diethylamino)sulfur trifluoride → Ethyl 3-(benzyl(cyclohexyl)amino)-2-fluoro-2-methylpropanoate
Reaction equation
[CH2:1]([N:8]([CH:18]1[CH2:23][CH2:22][CH2:21][CH2:20][CH2:19]1)[CH2:9][C:10](O)([CH3:16])[C:11]([O:13][CH2:14][CH3:15])=[O:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CCN(S(F)(F)[F:30])CC>ClCCl>[CH2:1]([N:8]([CH:18]1[CH2:23][CH2:22][CH2:21][CH2:20][CH2:19]1)[CH2:9][C:10]([F:30])([CH3:16])[C:11]([O:13][CH2:14][CH3:15])=[O:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
4
Procedure
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.