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-f269ae9cf3f44386bb978edb894cba8c
- Source dataset
- uspto-grants-2003_03
- Patent number
- US06538002B1
Reaction notes
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