Dibromodifluoromethane → HCID 11608680, compound

Participants

Reaction Steps

To a solution of 4-oxo-piperidine-1-carboxylic acid benzyl ester (0.50 g, 2.14 mmol, 1.0 eq.) in THF (20 mL) was added dibromodifluoromethane (0.90 mL, 4.5 eq.) at −30° C. followed by HMPA (1.75 mL, 4.5 eq.). The cooling bath was removed and the reaction mixture was swirled periodically. After 30 min, zinc dust (0.63 g, 4.5 eq.) and HMPA (80 μL 0.4 eq.) was added and the mixture was heated at reflux for 18 h. Upon cooling to room temperature, the residue was washed with diethyl ether several times. The combined ether washings were washed successively with saturated aqueous copper (II) sulphate, brine, dried over Na2SO4 and concentrated. The residue was purification by chromatography (20% EtOAc-hexanes) to afford 4-difluoromethylene-piperidine-1-carboxylic acid benzyl ester (0.32 g, 56%) as a colorless oil.

Provenance & Evidence