tert-Butyl 4-oxopiperidine-1-carboxylate → Tert-butyl 4-(4-chloro-2-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)phenyl)-4-hydroxypiperidine-1-carboxylate
Reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=1[C:9]1[O:10][CH2:11][C:12]([CH3:15])([CH3:14])[N:13]=1.C([Li])CCC.[C:21]([O:25][C:26]([N:28]1[CH2:33][CH2:32][C:31](=[O:34])[CH2:30][CH2:29]1)=[O:27])([CH3:24])([CH3:23])[CH3:22]>O1CCCC1>[C:21]([O:25][C:26]([N:28]1[CH2:33][CH2:32][C:31]([C:2]2[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=2[C:9]2[O:10][CH2:11][C:12]([CH3:15])([CH3:14])[N:13]=2)([OH:34])[CH2:30][CH2:29]1)=[O:27])([CH3:24])([CH3:22])[CH3:23]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -78 °C
Procedure
To a cold (−78° C.) solution of the product of step 1 (1.09 g, 4.63 mmol) in anhydrous tetrahydrofuran (10 mL) was added a solution of n-butyllithium (1.6 M in hexanes, 2.89 mL, 4.63 mmol) and the contents of the reaction were allowed to react for 0.5 h. A solution of 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (922 mg, 4.63 mmol) in tetrahydrofuran (10 mL) was added and the combined contents stirred for 2 h at −78° C. Reaction was quenched by the addition of saturated aqueous ammonium chloride (30 mL), followed by warming to rt. The biphasic mixture was extracted with ethyl acetate (150 mL); washed with water and brine; dried over magnesium sulfate; filtered and concentrated. 4-[4-Chloro-2-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)-phenyl]-4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester was isolated (412 mg, 22%) following silica gel chromatography (80% hexanes/20% ethyl acetate).
Workup
- customto react for 0.5 h
- customReaction
- customwas quenched by the addition of saturated aqueous ammonium chloride (30 mL)
- temperatureby warming to rt
- extractionThe biphasic mixture was extracted with ethyl acetate (150 mL)
- washwashed with water and brine
- dry with materialdried over magnesium sulfate
- filtrationfiltered
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-b8987849d3594b46abcd5ed5c746dee8
- Source dataset
- uspto-grants-2007_03
- Patent number
- US07186729B2
Reaction notes
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