反应详情

To a solution of (R)-3-(benzylamino)-1,1,1-trifluoropropan-2-ol (4-2, 5 g, 22.81 mmol) in CH3CN (200 ml) was added DIEA (12 ml, 68.7 mmol), (S)-2-chloropropionic acid (2.4 ml, 27.4 mmol), then 2,4,6-tripropyl-1,3,5,2,4,6-trioxatriphosphorinane-2,4,6-trioxide (16.3 ml, 27.4 mmol) slowly at rt. After 2.5 hr the mixture was concentrated. The material was taken up in EtOAc and washed with saturated NaHCO3, H2O, and brine. The organic layer was filtered through a pad of silica gel washing with ethyl acetate then concentrated to afford (S)—N-benzyl-2-hydroxy-N—((R)-3,3,3-trifluoro-2-hydroxypropyl)propanamide (4-3) as a clear oil which was sufficiently pure for use in the next step.

1. customslowly at rt
2. concentrationAfter 2.5 hr the mixture was concentrated
3. washwashed with saturated NaHCO3, H2O, and brine
4. filtrationThe organic layer was filtered through a pad of silica gel washing with ethyl acetate
5. concentrationthen concentrated