Diisopropylamine → 3-Phenyl-2-t-butylcarboxymethylpropionic acid, ethyl ester
Reaction equation
C(N[CH:5]([CH3:7])[CH3:6])(C)C.[CH2:8]([Li])CCC.[C:13]([O:23][CH2:24][CH3:25])(=[O:22])[CH2:14][CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.Br[CH2:27][C:28]([O:30]C(C)(C)C)=[O:29]>O1CCCC1.CCCCCC>[C:16]1([CH2:15][C:14]([CH2:27][C:28]([OH:30])=[O:29])([C:5]([CH3:6])([CH3:7])[CH3:8])[C:13]([O:23][CH2:24][CH3:25])=[O:22])[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1Participants
7
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- -78 °C
Procedure
Dissolve diisopropylamine (3.5 mL, 25 mmol) in tetrahydrofuran (30 mL). Add n-butyllithium (14 mL of a 1.6M solution in hexane, 22.4 mmol). Stir for 15 minutes and cool to -78° C. Add, by dropwise addition, ethyl dihydrocinnamate (3.5 mL, 20 mmol) and stir for 30 minutes. Add t-butyl bromoacetate (4.0 mL, 25 mmol) and gradually warm to room temperature overnight. Quench the solution with ammonium chloride solution (10 mL) and partition between water (25 mL) and ethyl ether (50 mL). Separate the organic phase, dry (MgSO4) and evaporate the solvent in vacuo. Purify by silica gel chromatography (5% ethyl acetate/hexane) to give 3-phenyl -2-t-butylcarboxymethylpropionic acid, ethyl ester as a pale yellow oil (2.68 g, 46%).
Workup
- stirringstir for 30 minutes
- customQuench the solution with ammonium chloride solution (10 mL)
- custompartition between water (25 mL) and ethyl ether (50 mL)
- customSeparate the organic phase
- dry with materialdry (MgSO4)
- customevaporate the solvent in vacuo
- customPurify by silica gel chromatography (5% ethyl acetate/hexane)
Sources & evidence
- ORD record
- ord-afc23055498143a996f97237774e972b
- Source dataset
- uspto-grants-1995_10
- Patent number
- US05455242
Reaction notes
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