Imidazole → [(1S)-1-(t-butyldiphenylsilyloxy)-2-methyl-propyl]-carbamic acid benzyl ester

HRID 891647

Reaction equation

HRID 891647 reaction equation
[CH2:1]([O:8][C:9](=[O:17])[NH:10][C@H:11](CO)[CH:12]([CH3:14])[CH3:13])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Si:18](Cl)([C:31]([CH3:34])([CH3:33])[CH3:32])([C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1.N1C=CN=C1.CN(C)C=[O:44]>>[CH2:1]([O:8][C:9](=[O:17])[NH:10][C@@H:11]([O:44][Si:18]([C:31]([CH3:34])([CH3:33])[CH3:32])([C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)[CH:12]([CH3:13])[CH3:14])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 4

HCID 795ImidazoleHCID 6228DimethylformamideHCID 94078tert-ButyldiphenylchlorosilaneHCID 10900657(S)-N-CBZ-valinol

Product 1

HCID 69543908[(1S)-1-(t-butyldiphenylsilyloxy)-2-methyl-propyl]-carbamic acid benzyl esterYield 100%

Procedure

Subsequently, to a solution of [(1S)-1-(hydroxymethyl)-2-methylpropyl]carbamic acid benzyl ester (4.56 g, 19.2 mmol) in dimethylformamide (140 ml) were added t-butyldiphenylsilyl chloride (6.00 ml, 23.1 mmol) and imidazole (1.57 g, 23.1 mmol) in an ice bath, and the resulting mixture was stirred at room temperature for 4 hours. After checking the completion of the reaction, the reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution. The organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using n-hexane:ethyl acetate (8:1→6:1) as the eluant to afford [(1S)-1-(t-butyldiphenylsilyloxy)-2-methyl-propyl]-carbamic acid benzyl ester (10.1 g, yield 100%) as white crystals.

Workup

  1. customthe completion of the reaction
  2. customthe reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution
  3. washThe organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution
  4. dry with materialdried over anhydrous sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by chromatography on a silica gel column

Sources & evidence

ORD record
ord-e825b6231e784d07b62eb4d40dc7d879
Source dataset
uspto-grants-2006_02
Patent number
US07001897B2

Linked notes

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