N-trans-BOC-(3S)-Fluoropyrrolidine

83220-73-9

479253-00-4

1. Fluorination: To a solution of tert-butyl (3R)-3-hydroxypyrrolidine-1-carboxylate (2.62 g) in dichloromethane (50 mL) was slowly added diethylaminosulfur trifluoride (2.22 mL) at -78°C. The mixture was gradually brought to room temperature and stirred for 75 minutes. The reaction mixture was gradually brought to room temperature and stirred for 75 minutes. 2. Post-treatment: The reaction mixture was poured into ice water and the organic layer was separated. The organic layer was dried with anhydrous magnesium sulfate and filtered to remove the desiccant. 3. Purification: The solvent was removed by evaporation under reduced pressure and the resulting residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate gradient) to afford tert-butyl (3S)-3-fluoropyrrolidine-1-carboxylate (676 mg, 26% yield) as an oily product. 4. 4. Product characterization: 1H-NMR (400 MHz, CDCl3) δ: 1.45 (9H, s), 2.17-2.26 (1H, m), 3.52-3.68 (5H, m), 5.20 (1H, dt, J = 52.7, 3.4 Hz).