Sodium Hydroxide → 2-chloro-1-(2-ethoxyethyl)-1H-benzimidazole

HRID 637012Notes

Reaction equation

HRID 637012 reaction equation
O[C:2]1[N:6]([CH2:7][CH2:8][O:9][CH2:10][CH3:11])[C:5]2[CH:12]=[CH:13][CH:14]=[CH:15][C:4]=2[N:3]=1.P(Cl)(Cl)([Cl:18])=O.[OH-].[Na+]>C(OCC)(=O)C>[Cl:18][C:2]1[N:6]([CH2:7][CH2:8][O:9][CH2:10][CH3:11])[C:5]2[CH:12]=[CH:13][CH:14]=[CH:15][C:4]=2[N:3]=1

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 178467919HCID 178467919, compound

Product 1

HCID 104893562-chloro-1-(2-ethoxyethyl)-1H-benzimidazole

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

Combine 2-hydroxy-1-(2-ethoxyethyl)-1H-benzimidazole (36.4 g, 177 mmol) and phosphorous oxychloride (72 mL) and reflux. After 30 minutes, cool to ambient temperature and pour the reaction mixture onto crushed ice. Adjust the pH to about 9 using aqueous 50% sodium hydroxide solution. Extract three times with ethyl acetate. Combine the organic layers and extract with brine. Dry the organic layer over Na2SO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting with ethyl acetate to give the 2-chloro-1-(2-ethoxyethyl)-1H-benzimidazole.

Workup

  1. additionpour the reaction mixture
  2. customonto crushed ice
  3. extractionExtract three times with ethyl acetate
  4. extractionextract with brine
  5. dry with materialDry the organic layer over Na2SO4
  6. filtrationfilter
  7. customevaporate in vacuo
  8. customto give a residue

Sources & evidence

ORD record
ord-4279d9d45fbb421cb9d1380d5a43d787
Source dataset
uspto-grants-2001_02
Patent number
US06194406B1

Reaction notes

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