Acetic Acid → 4-(1H-benzimidazol-2-yl)phenol

HRID 986677Notes

Reaction equation

HRID 986677 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].[C:9]1([C:15](=N)O)[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.C(O)(=[O:20])C>>[NH:7]1[C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][C:1]=2[N:8]=[C:15]1[C:9]1[CH:14]=[CH:13][C:12]([OH:20])=[CH:11][CH:10]=1

Participants

4

Reactant 3

HCID 176Acetic AcidHCID 7243O-PhenylenediamineHCID 178513622HCID 178513622, compound

Product 1

HCID 6756244-(1H-benzimidazol-2-yl)phenolYield 73%

Procedure

A mixture of 324 g (0.3 mol) of o-phenylenediamine, 67.5 g (0.36 mol) of benzene carboximidoic acid, 4 hydroxy-, methyl ester hydrochloride and 450 ml of glacial acetic acid was stirred at reflux for two hours. After standing overnight at room temperature the hydrochloride salt of the benzimidazole was collected by filtration, washed with acetic acid, and finally ether. The hydrochloride salt of the product was suspended in 450 ml of dilute ammonium hydroxide, stirred for one hour at room temperature, and chilled briefly. The product was collected and the filter cake was treated with charcoal during recrystallization from a 2:1 water-alcohol mixture. Filtration gave 45.9 g (73%) of 4-(1H-benzimidazol-2-yl)phenol (mp 286°-289° C.) and a second crop of 2.8 g on standing.

Workup

  1. temperatureat reflux for two hours
  2. filtrationthe hydrochloride salt of the benzimidazole was collected by filtration
  3. washwashed with acetic acid, and finally ether
  4. stirringstirred for one hour at room temperature
  5. temperaturechilled briefly
  6. customThe product was collected
  7. additionthe filter cake was treated with charcoal during recrystallization from a 2:1 water-alcohol mixture
  8. filtrationFiltration

Sources & evidence

ORD record
ord-0bd6cdcbfc88413f8bae70a22b1ee41e
Source dataset
uspto-grants-1987_12
Patent number
US04714762

Reaction notes

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