(Diethylamino)sulfur trifluoride → rac-(3S*,5S*)-5-(2,6-dimethoxyphenyl)-3-fluoro-1-(4-(trifluoromethoxy)benzyl)pyrrolidin-2-one

Participants

Reaction Conditions

Reaction Steps

A cooled (−78° C.) mixture of DAST (117 mg; 0.72 mmol) in anh. DCM (0.5 ml) was treated dropwise with a solution of rac-(3R*,5S*)-5-(2,6-dimethoxyphenyl)-3-hydroxy-1-(4-(trifluoromethoxy)benzyl)-pyrrolidin-2-one (100 mg; 0.24 mmol) in anh. DCM (0.5 ml). The resulting mixture was further stirred at −78° C., under nitrogen, for 1 h, at 0° C. for 30 min., and finally at rt for 1 h. Aq. sat. NaHCO3 was added, and the resulting mixture was extracted with DCM. The mixed organic layers were dried over anh. MgSO4, filtered, and concentrated to dryness under reduced pressure. Purification by preparative HPLC afforded rac-(3S*,5S*)-5-(2,6-dimethoxyphenyl)-3-fluoro-1-(4-(trifluoromethoxy)benzyl)pyrrolidin-2-one as a colorless solid. LC-MS (conditions A): tR=0.90 min.; [M+H]+: 414.12 g/mol.

Provenance & Evidence