Ethyl bromoacetate → tert-Butyl 3-(2-ethoxy-2-oxoethyl)-4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylate

HRID 1628388Notes

Reaction equation

HRID 1628388 reaction equation
[CH2:1]([CH:3]([C:6]1[C:14]2[NH:13][C:12](=[O:15])[N:11]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[C:10]=2[CH:9]=[CH:8][CH:7]=1)[CH2:4][CH3:5])[CH3:2].C(=O)([O-])[O-].[K+].[K+].Br[CH2:30][C:31]([O:33][CH2:34][CH3:35])=[O:32]>CN(C)C=O.O>[CH2:34]([O:33][C:31](=[O:32])[CH2:30][N:13]1[C:14]2[C:6]([CH:3]([CH2:4][CH3:5])[CH2:1][CH3:2])=[CH:7][CH:8]=[CH:9][C:10]=2[N:11]([C:16]([O:18][C:19]([CH3:20])([CH3:22])[CH3:21])=[O:17])[C:12]1=[O:15])[CH3:35]

Participants

6

Reactant 3

HCID 7748Ethyl bromoacetateHCID 11430Potassium CarbonateHCID 67272646tert-Butyl 4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylate

Product 1

HCID 68548443tert-Butyl 3-(2-ethoxy-2-oxoethyl)-4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylateYield 98%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

To a solution of tert-butyl 4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylate (Reference Example 7; 4.94 g, 16.2 mmol) in N,N-dimethylformamide (40 mL) were added potassium carbonate (2.47 g, 17.9 mmol) and ethyl bromoacetate (1.98 mL, 17.9 mmol), and the mixture was stirred at room temperature for 3 hr. The reaction mixture was diluted with water and extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 5-20% ethyl acetate/n-hexane gradient mixture to give the title compound (6.17 g, 15.8 mmol, 98%) as a colorless oil.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe organic layer was washed with brine
  3. dry with materialdried over anhydrous sodium sulfate
  4. concentrationconcentrated in vacuo
  5. customThe residue was purified by silica gel column chromatography
  6. washeluting with a 5-20% ethyl acetate/n-hexane gradient mixture

Sources & evidence

ORD record
ord-1918e4077c384554af29cd04824badb9
Source dataset
uspto-grants-2014_07
Patent number
US08785460B2

Reaction notes

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