Sodium hydride → Tert-butyl (2-oxo-2,3-dihydrobenzimidazol-1-yl)acetate

HRID 656398Notes

Reaction equation

HRID 656398 reaction equation
[OH:1][C:2]1[NH:3][C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=1.Br[CH2:12][C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14].[H-].[Na+]>CN(C=O)C>[O:1]=[C:2]1[N:6]([CH2:12][C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[C:5]2[CH:7]=[CH:8][CH:9]=[CH:10][C:4]=2[NH:3]1

Participants

5

Reactant 3

HCID 24758Sodium hydrideHCID 79177tert-Butyl bromoacetateHCID 178517141HCID 178517141, compound

Product 1

HCID 20814117Tert-butyl (2-oxo-2,3-dihydrobenzimidazol-1-yl)acetate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
0 °C

Procedure

To a stirred mixture of 2-hydroxybenzimidazole (4.00 g, 29.8 mmol) and tert-butyl bromoacetate (5.53 g, 28.3 mmol) in DMF (50 mL) at 0° C. was added sodium hydride (1.31 g of a 60% dispersion in mineral oil, 32.8 mmol). The mixture was stirred at 0° C. for 1 h, then quenched with saturated aqueous NaHCO3 and concentrated in vacuo. The residue was partitioned between EtOAc (500 mL) and H2O (300 mL) and the organic layer was dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel chromatography, eluting with a gradient of CH2Cl2:EtOAc—100:0 to 0:100, to give the title compound. MS: m/z=249 (M+1).

Workup

  1. customquenched with saturated aqueous NaHCO3
  2. concentrationconcentrated in vacuo
  3. customThe residue was partitioned between EtOAc (500 mL) and H2O (300 mL)
  4. dry with materialthe organic layer was dried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe crude product was purified by silica gel chromatography
  8. washeluting with a gradient of CH2Cl2

Sources & evidence

ORD record
ord-3f616e7d4a1740cb9dc83a48d39e1273
Source dataset
uspto-grants-2011_12
Patent number
US08071771B2

Reaction notes

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