Ethyl bromoacetate → tert-butyl(2S)-2-[(2-ethoxy-2-oxoethyl)amino]-3,3-dimethylbutanoate
Reaction equation
Cl.[C:2]([O:6][C:7](=[O:14])[C@H:8]([C:10]([CH3:13])([CH3:12])[CH3:11])[NH2:9])([CH3:5])([CH3:4])[CH3:3].C(N(CC)CC)C.Br[CH2:23][C:24]([O:26][CH2:27][CH3:28])=[O:25]>CN(C=O)C>[CH2:27]([O:26][C:24](=[O:25])[CH2:23][NH:9][C@@H:8]([C:10]([CH3:13])([CH3:12])[CH3:11])[C:7]([O:6][C:2]([CH3:5])([CH3:4])[CH3:3])=[O:14])[CH3:28]Participants
5
Procedure
A solution of L-tert-leucine tert-butyl ester hydrochloride (5 g, 22.34 mmol) in DMF (25 mL) was treated with triethylamine (3.1 mL, 22.34 mmol) and the mixture was stirred for 1 hour. The reaction was filtered to remove solid salts, and the filtrate was treated with triethylamine (9.3 mL, 67.0 mmol) and ethyl bromoacetate (9.9 mL, 67.0 mmol), and the reaction was stirred for 3 hours at 25° C. The solvent was concentrated and the reaction was partitioned between dichloromethane and water. The organic phase was washed with brine and dried over MgSO4, filtered and concentrated. The residue was chromatographed on silica gel eluting with 0-20% ethyl acetate/hexane to give the title compound (5.47 g, 90% yield).
Workup
- filtrationThe reaction was filtered
- customto remove solid salts
- stirringthe reaction was stirred for 3 hours at 25° C
- concentrationThe solvent was concentrated
- customthe reaction was partitioned between dichloromethane and water
- washThe organic phase was washed with brine
- dry with materialdried over MgSO4
- filtrationfiltered
- concentrationconcentrated
- customThe residue was chromatographed on silica gel eluting with 0-20% ethyl acetate/hexane
Sources & evidence
- ORD record
- ord-a344a4d5500e4265bf319bf8d439d8ab
- Source dataset
- uspto-grants-2010_11
- Patent number
- US07834043B2
Reaction notes
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