Benzimidazole → 1-(2-Chloroethyl)-1H-benzimidazole

HRID 1654163Notes

Reaction equation

HRID 1654163 reaction equation
[N:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[NH:3][CH:2]=1.Br[CH:11]([Cl:13])[CH3:12].C(=O)([O-])[O-].[K+].[K+].CN(C)C=O>O.C(OCC)(=O)C>[Cl:13][CH2:11][CH2:12][N:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[CH:2]1

Participants

7

Reactant 4

HCID 5798BenzimidazoleHCID 6228DimethylformamideHCID 11430Potassium CarbonateHCID 116541-Bromo-1-chloroethane

Product 1

HCID 5831471-(2-Chloroethyl)-1H-benzimidazoleYield 77%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Procedure

A mixture of benzimidazole (4.72g, 40 mmol), bromochloroethane (3.4 ml, 41 mmol), potassium carbonate (5.52 g, 40 mmol) and dimethylformamide (60 ml) was stirred at room temperature for 20 hours. To the reaction mixture were added ethyl acetate and water, which was extracted with ethyl acetate. The organic layer was washed with water and then with a saturated aqueous sodium chloride solution, followed by drying (anhydrous sodium sulfate). The solvent was distilled off, and the residue was subjected to a silica gel chromatography (3.0×40 cm: ethyl acetate-hexane=2:1) to give 1-(2-chloroethyl)benzimidazole (5.56 g, 38%) as a colorless oily substance.

Workup

  1. extractionwas extracted with ethyl acetate
  2. washThe organic layer was washed with water
  3. dry with materialby drying (anhydrous sodium sulfate)
  4. distillationThe solvent was distilled off

Sources & evidence

ORD record
ord-730e7c9ea6a242f3906623ebbf372e81
Source dataset
uspto-grants-1995_04
Patent number
US05405861

Reaction notes

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