Cesium carbonate → Tert-butyl 3-tert-butoxycarbonylmethyl-5-iodo-2-oxo-2,3-dihydrobenzimidazole-1-carboxylate

HRID 1631955Notes

Reaction equation

HRID 1631955 reaction equation
[I:1][C:2]1[CH:18]=[CH:17][C:5]2[N:6]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[C:7](=[O:9])[NH:8][C:4]=2[CH:3]=1.Br[CH2:20][C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22].C(=O)([O-])[O-].[Cs+].[Cs+]>C(#N)C>[C:24]([O:23][C:21]([CH2:20][N:8]1[C:4]2[CH:3]=[C:2]([I:1])[CH:18]=[CH:17][C:5]=2[N:6]([C:10]([O:12][C:13]([CH3:14])([CH3:15])[CH3:16])=[O:11])[C:7]1=[O:9])=[O:22])([CH3:27])([CH3:26])[CH3:25]

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 79177tert-Butyl bromoacetateHCID 66755179Tert-butyl 5-iodo-2-oxo-2,3-dihydrobenzimidazole-1-carboxylate

Product 1

HCID 66755429Tert-butyl 3-tert-butoxycarbonylmethyl-5-iodo-2-oxo-2,3-dihydrobenzimidazole-1-carboxylate

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A mixture of 1.90 g (5.27 mmol) of tert-butyl 5-iodo-2-oxo-2,3-dihydro-benzimidazole-1-carboxylate (VIb), 1.13 g (5.80 mmol) of tert-butyl bromoacetate and 2.23 g (6.86 mmol) of cesium carbonate in acetonitrile (60 ml) was heated under reflux for 3 h. The solvent was removed in vacuo, water was added to the residue, and the aqueous mixture was extracted four times with ethyl acetate. The combined organic phases were washed with saturated NaCl solution and dried over magnesium sulfate, and the solvent was removed in vacuo. The residue was purified by chromatography on silica gel (mobile phase gradient 15-40% ethyl acetate in heptane). Yield: 2.26 g (90%) of white solid.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 3 h
  3. customThe solvent was removed in vacuo, water
  4. additionwas added to the residue
  5. extractionthe aqueous mixture was extracted four times with ethyl acetate
  6. washThe combined organic phases were washed with saturated NaCl solution
  7. dry with materialdried over magnesium sulfate
  8. customthe solvent was removed in vacuo
  9. customThe residue was purified by chromatography on silica gel (mobile phase gradient 15-40% ethyl acetate in heptane)

Sources & evidence

ORD record
ord-8b3620a69ed74c52a75f5527d44bfdba
Source dataset
uspto-grants-2014_07
Patent number
US08791148B2

Reaction notes

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