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

HRID 1631948Notes

Reaction equation

HRID 1631948 reaction equation
[Cl: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]([Cl: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 10468275tert-Butyl 5-chloro-2-oxo-2,3-dihydrobenzimidazole-1-carboxylate

Product 1

HCID 66754580Tert-butyl 3-tert-butoxycarbonylmethyl-5-chloro-2-oxo-2,3-dihydrobenzimidazole-1-carboxylate

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A mixture of 4.00 g (14.9 mmol) of tert-butyl 5-chloro-2-oxo-2,3-dihydrobenzimidazole-1-carboxylate (VIa), 3.19 g (16.4 mmol) of tert-butyl bromoacetate and 7.28 g (22.3 mmol) of cesium carbonate in acetonitrile (80 ml) was heated under reflux for 3 h. The solvent was removed in vacuo, the residue was mixed with water, 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 0-5% ethyl acetate in dichloromethane).

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 3 h
  3. customThe solvent was removed in vacuo
  4. additionthe residue was mixed with water
  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 0-5% ethyl acetate in dichloromethane)

Sources & evidence

ORD record
ord-780528ff1e4f454b977113e63bbb71a1
Source dataset
uspto-grants-2014_07
Patent number
US08791148B2

Reaction notes

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