Water → 2-Chlorobenzimidazole

HRID 2210826Notes

Reaction equation

HRID 2210826 reaction equation
O[C:2]1[NH:3][C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=1.O.[OH-].[Na+].P(Cl)(Cl)([Cl:16])=O>>[Cl:16][C:2]1[NH:3][C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=1

Participants

5

Reactant 4

HCID 962WaterHCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 178517141HCID 178517141, compound

Product 1

HCID 785722-Chlorobenzimidazole

Procedure

A solution of 2-hydroxy benzimidazole (40.2 g) in 93 ml phosphorus oxychloride is heated to reflux under stirring for 6 hours. After achievement of the reaction the solution is let to revert to -10° C. and hydrolysed with 100 g crushed ice and 100 ml iced water. They are slowly added 249 ml sodium hydroxide 10N to get a neutral pH value. The precipitated product is filtered, washed with the minimal amount of water. The crystals are taken up in hot ethanol. After cooling, the alcoholic juice are filtered and concentrated to dryness.

Workup

  1. temperatureto reflux
  2. customAfter achievement of the reaction the solution
  3. customto revert to -10° C. and hydrolysed with 100 g
  4. customto get a neutral pH value
  5. filtrationThe precipitated product is filtered
  6. washwashed with the minimal amount of water
  7. temperatureAfter cooling
  8. filtrationthe alcoholic juice are filtered
  9. concentrationconcentrated to dryness

Sources & evidence

ORD record
ord-ce7d920126024a3ba5410d9495c4e2bd
Source dataset
uspto-grants-1995_10
Patent number
US05461059

Reaction notes

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