Dibromodifluoromethane → HCID 11608680, compound
Reaction equation
[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][C:14](=O)[CH2:13][CH2:12]1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Br[C:19](Br)([F:21])[F:20].CN(P(N(C)C)(N(C)C)=O)C>C1COCC1.[Zn]>[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][C:14](=[C:19]([F:21])[F:20])[CH2:13][CH2:12]1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
Procedure
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.
Workup
- customThe cooling bath was removed
- temperaturethe mixture was heated
- temperatureat reflux for 18 h
- washthe residue was washed with diethyl ether several times
- washThe combined ether washings were washed successively with saturated aqueous copper (II) sulphate, brine
- dry with materialdried over Na2SO4
- concentrationconcentrated
- custompurification by chromatography (20% EtOAc-hexanes)
Sources & evidence
- ORD record
- ord-5f3e68e6871846ea8dc42b90748725da
- Source dataset
- uspto-grants-2011_01
- Patent number
- US07868002B2
Reaction notes
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