Imidazole → (aR)-a-[[(1,1-Dimethylethoxy)carbonyl]amino]-4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]benzeneacetic Acid

HRID 454980Notes

Reaction equation

HRID 454980 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([C:13]1[CH:18]=[CH:17][C:16]([OH:19])=[CH:15][CH:14]=1)[C:10]([OH:12])=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].N1C=CN=C1.[Si:25](Cl)([C:28]([CH3:31])([CH3:30])[CH3:29])([CH3:27])[CH3:26]>CN(C=O)C.CCOC(C)=O>[C:1]([O:5][C:6]([NH:8][C@H:9]([C:13]1[CH:18]=[CH:17][C:16]([O:19][Si:25]([C:28]([CH3:31])([CH3:30])[CH3:29])([CH3:27])[CH3:26])=[CH:15][CH:14]=1)[C:10]([OH:12])=[O:11])=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

6

Reactant 3

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chloride2×HCID 11821572Boc-4-hydroxy-D-phenylglycine

Product 1

HCID 86658147(aR)-a-[[(1,1-Dimethylethoxy)carbonyl]amino]-4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]benzeneacetic AcidYield 123.5%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of (R)-tert Butoxycarbonylamino-(4-hydroxy-phenyl)-acetic acid (2.54 g, 9.55 mmol) in DMF (5 mL) was added imidazole (1.43 g, 21 mmol) followed by t-butyldimethylsilyl chloride (1.58 g, 10.5 mmol). The resulting mixture was stirred at rt for overnight. Additional t-butyldimethylsilyl chloride (1.43 g, 9.55 mmol) was added and let the reaction continue for another hour. The reaction mixture was diluted with EtOAc and washed with H2O three times and concentrated. To the residue was added aqueous 1N NaOH and then acidified with concentrated HCl. The resulting mixture was extracted with EtOAc three times. The combined organic layer was dried (MgSO4) and concentrated to provide the titled compound (4.5 g).

Workup

  1. waitcontinue for another hour
  2. washwashed with H2O three times
  3. concentrationconcentrated
  4. additionTo the residue was added aqueous 1N NaOH
  5. extractionThe resulting mixture was extracted with EtOAc three times
  6. dry with materialThe combined organic layer was dried (MgSO4)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-2a1287e2a01740aa9b86ce2706ea1673
Source dataset
uspto-grants-2013_07
Patent number
US08497271B2

Reaction notes

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