Benzyl Bromide → 1-benzyl-4-(4-bromo-1H-pyrazol-1-yl)piperidine
Reaction equation
[CH2:1](Br)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(=O)([O-])[O-].[K+].[K+].[Br:15][C:16]1[CH:17]=[N:18][N:19]([CH:21]2[CH2:26][CH2:25][NH:24][CH2:23][CH2:22]2)[CH:20]=1>CN(C=O)C>[CH2:1]([N:24]1[CH2:23][CH2:22][CH:21]([N:19]2[CH:20]=[C:16]([Br:15])[CH:17]=[N:18]2)[CH2:26][CH2:25]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
Procedure
Benzyl bromide (0.42 mL, 3.56 mmol) and potassium carbonate (670 mg, 4.85 mmol) were added to a solution of 4-(4-bromo-1H-pyrazol-1-yl)piperidine (743.7 mg, 3.23 mmol) in DMF (10 mL), and the reaction stirred at room temperature overnight. The reaction was quenched with the addition of water (50 mL) and extracted with ethyl acetate (3×50 mL). The organic extracts were combined and washed with water (2×50 mL) and brine (30 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The crude product was purified directly via column chromatography on silica gel (Biotage 25 g column, gradient elution with 20-30% ethyl acetate in hexanes) to afford 1-benzyl-4-(4-bromo-1H-pyrazol-1-yl)piperidine (673 mg, 65%) as a light yellow oil. MS (ESI, pos. ion) m/z 321 [M+H]+.
Workup
- customThe reaction was quenched with the addition of water (50 mL)
- extractionextracted with ethyl acetate (3×50 mL)
- washwashed with water (2×50 mL) and brine (30 mL)
- dry with materialdried over anhydrous sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
- customThe crude product was purified directly via column chromatography on silica gel (Biotage 25 g column, gradient elution with 20-30% ethyl acetate in hexanes)
Sources & evidence
- ORD record
- ord-a2b2ec1f61234187810361190f67c292
- Source dataset
- uspto-grants-2016_07
- Patent number
- US09388161B2
Reaction notes
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