4-Nitrobenzoic Acid → rac-(3R*,5S*)-5-(2,6-dimethoxyphenyl)-2-oxo-1-(4-(trifluoromethoxy)benzyl)-pyrrolidin-3-yl 4-nitrobenzoate

Participants

Reaction Conditions

Reaction Steps

A cooled (0° C.) mixture of rac-(3S*,5S*)-5-(2,6-dimethoxyphenyl)-3-hydroxy-1-(4-(trifluoromethoxy)benzyl)pyrrolidin-2-one (1.260 g; 3.06 mmol), 4-nitrobenzoic acid (1.023 g; 6.12 mmol), and PPh3 (1.767 g; 6.73 mmol) in anh. THF (50 ml) was treated dropwise with a solution of DEAD (1.173 g; 6.73 mmol) in anh. THF (10 ml). The resulting mixture was further stirred at 0° C., under nitrogen, for 5 min., and then at rt for 4 h. Concentration to dryness under reduced pressure, and subsequent purification by FC (toluene/AcOEt=5/1) afforded rac-(3R*,5S*)-5-(2,6-dimethoxyphenyl)-2-oxo-1-(4-(trifluoromethoxy)benzyl)-pyrrolidin-3-yl 4-nitrobenzoate as a colorless solid. LC-MS (conditions A): tR=1.02 min.; [M+H]+: 561.17 g/mol.

Provenance & Evidence