Sodium Fluoride → tert-butyl(2S,4R)-2-[(dimethylamino)carbonyl]-4-fluoropyrrolidine-1-carboxylate

Participants

Reaction Steps

To a suspension of 25.7 g of the compound obtained in Step 6-1a and 5.00 g of sodium fluoride in dichloromethane (260 ml) was added dropwise under ice cooling a mixture (approximately 3:1) of 1,1,2,3,3,3-hexafluoro-1-(diethylamino)propane and 26.6 g 1,2,3,3,3-pentafluoro-1-(diethylamino)-2-propene over 10 minutes, then, the solution was stirred at room temperature for 16 hours. To the reaction solution was added an aqueous solution of 5% K2CO3 under ice cooling, and the resulting mixture was stirred for 30 minutes at the same temperature. After liquid separation, obtained aqueous layer was extracted with CHCl3, the combined organic layer was washed with saturated brine, dried over MgSO4, then, the drying agent was separated by filtration, and the solvent was evaporated under reduced pressure. The obtained residue was subjected to column chromatography (silicagel 60; mobile phase: EtOAc/n-hexane=1/1 to 10/0; v/v) to obtain 12.2 g of the title compound (pale yellow solid).

Provenance & Evidence