Cesium carbonate → 3-[3-(1-Ethoxycarbonyl-1-methyl-ethoxy)-4-methyl-phenyl]-piperidine-1-carboxylic acid benzyl ester
Reaction equation
[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][CH2:14][CH:13]([C:17]2[CH:22]=[CH:21][C:20]([CH3:23])=[C:19]([OH:24])[CH:18]=2)[CH2:12]1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(=O)([O-])[O-].[Cs+].[Cs+].[CH2:31]([O:33][C:34](=[O:39])[C:35](Br)([CH3:37])[CH3:36])[CH3:32]>CN(C)C=O.O>[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][CH2:14][CH:13]([C:17]2[CH:22]=[CH:21][C:20]([CH3:23])=[C:19]([O:24][C:35]([C:34]([O:33][CH2:31][CH3:32])=[O:39])([CH3:37])[CH3:36])[CH:18]=2)[CH2:12]1)=[O:10])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 60 °C
Procedure
To a solution of 3-(3-hydroxy-4-methyl-phenyl)-piperidine-1-carboxylic acid benzyl ester (2.02 g, 6.21 mmol) in 15 mL dimethylformamide was added cesium carbonate (4.05 g, 12.42 mmol) and ethyl-2-bromoisobutyrate (3.64 mL, 24.83 mmol). The mixture was heated to 60° C. under N2 with stirring for 18 h and cooled to ambient temperature. The resultant brown suspension was diluted with 300 mL water and extracted with diethyl ether (2×200 mL). The organic phases were combined and dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The resultant oil was flash chromatographed with 20% ethyl acetate/hexanes to yield 1.36 g (50%) of the desired 3-[3-(1-ethoxycarbonyl-1-methyl-ethoxy)-4-methyl-phenyl]-piperidine-1-carboxylic acid benzyl ester as a clear oil.
Workup
- temperaturecooled to ambient temperature
- extractionextracted with diethyl ether (2×200 mL)
- dry with materialdried over anhydrous sodium sulfate
- filtrationfiltered
- concentrationconcentrated under reduced pressure
- customchromatographed with 20% ethyl acetate/hexanes
Sources & evidence
- ORD record
- ord-7e813e1ac722429081728ee7c3f8f824
- Source dataset
- uspto-grants-2007_04
- Patent number
- US07199243B2
Reaction notes
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