tert-Butyl 4-oxopiperidine-1-carboxylate → HCID 21912813, compound
Reaction equation
[CH2:1]([N:3]1[C:11](Br)=[C:10]2[C:5]([CH:6]=[CH:7][CH:8]=[CH:9]2)=[N:4]1)[CH3:2].[Li]C(C)(C)C.[O:18]=[C:19]1[CH2:24][CH2:23][N:22]([C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])[CH2:21][CH2:20]1>C1COCC1>[C:28]([O:27][C:25]([N:22]1[CH2:23][CH2:24][C:19]([OH:18])([C:11]2[N:3]([CH2:1][CH3:2])[N:4]=[C:5]3[C:10]=2[CH:9]=[CH:8][CH:7]=[CH:6]3)[CH2:20][CH2:21]1)=[O:26])([CH3:31])([CH3:29])[CH3:30]Participants
Conditions
- Temperature
- -78 °C
Procedure
To a solution of 2-ethyl-3-bromoindazole (3.4 g, 15.18 mmol) in THF (30 mL) was added t-BuLi (1.7 M in pentane, 10.72 mL, 18.22 mmol) dropwise at −78° C. After stirring at −78° C. for 20 min., was added tert-butyl 4-oxo-1-piperidinecarboxylate (3.03 g, 15.18 mmol) in THF (10 mL) dropwise at −78° C. The mixture was stirred at −78° C. for 10 min. and at rt for 18 h. After the reaction was quenched with aq. NH4Cl, the mixture was partitioned between ethyl acetate and water. The aqueous layer was extracted with ethyl acetate (3×). The combined organic phases were washed with brine, and dried over anhydrous magnesium sulfate. Concentration followed by purification by flash chromatography (hexanes ethyl acetate=4:1, then 1:1) to give 1.18 g of the title compound as a foamy solid.
Workup
- stirringThe mixture was stirred at −78° C. for 10 min. and at rt for 18 h
- customAfter the reaction was quenched with aq. NH4Cl
- customthe mixture was partitioned between ethyl acetate and water
- extractionThe aqueous layer was extracted with ethyl acetate (3×)
- washThe combined organic phases were washed with brine
- dry with materialdried over anhydrous magnesium sulfate
- concentrationConcentration
- customfollowed by purification by flash chromatography (hexanes ethyl acetate=4:1
Sources & evidence
- ORD record
- ord-c9d0f6ec84804ac9b064301d98ccf8b8
- Source dataset
- uspto-grants-2002_03
- Patent number
- US06358979B1
Reaction notes
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