Potassium Carbonate → tert-butyl 3-(4-ethoxy-4-oxobutyl)-4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylate

HRID 1398757Notes

Reaction equation

HRID 1398757 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][CH2:31][CH2:32][C:33]([O:35][CH2:36][CH3:37])=[O:34]>CN(C)C=O>[CH2:36]([O:35][C:33](=[O:34])[CH2:32][CH2:31][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])[CH3:37]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 76300Ethyl 4-bromobutyrateHCID 67272646tert-Butyl 4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylate

Product 1

HCID 68763140tert-butyl 3-(4-ethoxy-4-oxobutyl)-4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylateYield 135.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
85 °C

Procedure

To a solution of tert-butyl 4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylate (Reference Example 7; 10.37 g, 34.11 mmol) in N,N-dimethylformamide (100 mL) was added potassium carbonate (5.18 g, 37.52 mmol) and ethyl 4-bromobutyrate (8.55 g, 37.52 mmol), and the mixture was stirred at 80-90° C. overnight. The reaction solution was concentrated to dryness and diluted with water (150 mL). The resulting mixture was extracted with ethyl acetate (100 mL×2). The combined extracts were washed with water (80 mL×2), brine (100 mL), dried over anhydrous sodium sulfate and concentrated in vacuo to give 19.3 g of crude tert-butyl 3-(4-ethoxy-4-oxobutyl)-4-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxylate, which was used for the next step without further purification.

Workup

  1. concentrationThe reaction solution was concentrated to dryness
  2. additiondiluted with water (150 mL)
  3. extractionThe resulting mixture was extracted with ethyl acetate (100 mL×2)
  4. washThe combined extracts were washed with water (80 mL×2), brine (100 mL)
  5. dry with materialdried over anhydrous sodium sulfate
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-b3164e32fa1049e98daad8aac8c9ae52
Source dataset
uspto-grants-2014_12
Patent number
US08901141B2

Reaction notes

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