Imidazole → Benzyl N-(2-t-Butyldimethylsilyloxy-1-methylethyl)-carbamate

HRID 1901673Notes

Reaction equation

HRID 1901673 reaction equation
[Si:1](Cl)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[CH2:9]([O:16][C:17]([NH:19][CH:20]([CH3:23])[CH2:21][OH:22])=[O:18])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1.N1C=CN=C1>CN(C)C=O>[Si:1]([O:22][CH2:21][CH:20]([NH:19][C:17](=[O:18])[O:16][CH2:9][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)[CH3:23])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 560855Benzyl (2-hydroxy-1-methylethyl)carbamate

Product 1

HCID 14308419Benzyl N-(2-t-Butyldimethylsilyloxy-1-methylethyl)-carbamateYield 96.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

A solution of 13.72 g of t-butyldimethylsilyl chloride in 50 ml of dimethylformamide was added dropwise, whilst ice-cooling, to a mixture of 16.0 g of 2-benzyloxycarbonylaminopropanol (prepared as described in Preparation 7), 12.39 g of imidazole and 150 ml of dimethylformamide. The mixture was then stirred at room temperature for 6.5 hours. At the end of this time, the dimethylformamide was removed from the reaction mixture by evaporation under reduced pressure, and water was added to the resulting residue, which was then extracted with ethyl acetate. The extract was washed with an aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. The ethyl acetate was removed from the extract by evaporation under reduced pressure, and the resulting residue was purified by silica gel column chromatography, using a 1:6 by volume mixture of ethyl acetate and hexane as the eluent, to give 23.89 g of the title compound, melting at 68.0° C. to 70.2° C.

Workup

  1. customAt the end of this time, the dimethylformamide was removed from the reaction mixture by evaporation under reduced pressure, and water
  2. additionwas added to the resulting residue, which
  3. extractionwas then extracted with ethyl acetate
  4. washThe extract was washed with an aqueous solution of sodium chloride
  5. dry with materialdried over anhydrous sodium sulfate
  6. customThe ethyl acetate was removed from the
  7. extractionextract by evaporation under reduced pressure
  8. customthe resulting residue was purified by silica gel column chromatography
  9. additionby volume mixture of ethyl acetate and hexane as the eluent

Sources & evidence

ORD record
ord-f9911c803a644619a07e92799eee64e3
Source dataset
uspto-grants-1996_11
Patent number
US05578620

Reaction notes

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