Imidazole → 5-(tert-butyl-dimethyl-silanyloxy)-1H-indole-2-carboxylic acid ethyl ester

HRID 2105328Notes

Reaction equation

HRID 2105328 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6]([C:11]([OH:13])=[O:12])=[CH:5]2.[C:14]([Si:18]([CH3:21])([CH3:20])Cl)([CH3:17])([CH3:16])[CH3:15].N1[CH:26]=[CH:25]N=C1.[Cl-].[NH4+]>CN(C)C=O>[CH2:25]([O:12][C:11]([C:6]1[NH:7][C:8]2[C:4]([CH:5]=1)=[CH:3][C:2]([O:1][Si:18]([C:14]([CH3:17])([CH3:16])[CH3:15])([CH3:21])[CH3:20])=[CH:10][CH:9]=2)=[O:13])[CH3:26]

Participants

6

Reactant 4

HCID 795ImidazoleHCID 25517Ammonium ChlorideHCID 28928tert-Butyldimethylsilyl chlorideHCID 889585-Hydroxyindole-2-carboxylic acid

Product 1

HCID 226767305-(tert-butyl-dimethyl-silanyloxy)-1H-indole-2-carboxylic acid ethyl esterYield 98.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To the solution of 10.0 g (49.0 mmol) 5-hydroxyindole-2-carboxylic acid (commercially available) in 30 ml N,N-dimethylformamide, 7.7 g (51.1 mmol) tert-butyldimethylchlorosilane and 3.5 g (51.4 mmoL) imidazole was added. After 1 hour, the solution was poured on 10% aqueous ammonium chloride solution and was extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was purified by column chromatography over silica gel with ethyl acetate:n-hexane (1:2 v/v) as eluant to give 15.3 g (98.5%) of the compound as a white solid.

Workup

  1. extractionwas extracted three times with ethyl acetate
  2. washThe combined organic layers were washed with brine
  3. dry with materialdried over magnesium sulfate
  4. filtrationfiltered
  5. customevaporated
  6. customThe residue was purified by column chromatography over silica gel with ethyl acetate:n-hexane (1:2 v/v) as eluant

Sources & evidence

ORD record
ord-f873a1f4b3a745e4a728a1816f38f6ec
Source dataset
uspto-grants-2009_08
Patent number
US07579351B2

Reaction notes

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