Toluene → 4-(1H-benzimidazol-2-yl)phenol

HRID 35982Notes

Reaction equation

HRID 35982 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[NH2:8].C1(S(C2C=CC=CC=2)(=O)=[O:16])C=CC=CC=1.[C:24]1([CH3:30])[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1>>[OH:16][C:27]1[CH:28]=[CH:29][C:24]([C:30]2[NH:1][C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=3[N:8]=2)=[CH:25][CH:26]=1

Participants

4

Reactant 3

HCID 1140TolueneHCID 7243O-PhenylenediamineHCID 31386Diphenyl sulfone

Product 1

HCID 6756244-(1H-benzimidazol-2-yl)phenolYield 64%

Conditions

Temperature
150 °C

Procedure

A mixture of 1,2-diaminobenzene (25.17 g, 0.233 mol), phenyl-4-hydroxphenylbenzoate (50.17 g, 0.234 mol), diphenylsulfone (121.15 g), and toluene (100 ml) were heated under a nitrogen atmosphere for 16 hours at 150° C. The toluene was removed and the temperature increased to 260° C. and maintained for two and one-half hours. A vacuum was subsequently applied and the temperature increased to 290° C. and maintained for one and one-half hours. The warm reaction mixture was precipitated in toluene, washed in hot toluene, and subsequently dried at 110° C. to afford 45.00 g (92% crude yield) of a red-tan powder, m.p. (DTA) 279° C. (broad). The solid was recrystallized from 40% aqueous ethanol using charcoal to afford a light tan crystalline product (31.46 g, 64% yield). The compound exhibited a sharp melt by DTA with an endothermic minimum at 280° C. Anal. calcd for C13H10N2O: C, 74.27%; H, 4.79%; N, 13.32%; Found: C, 74.21%; H, 4.75%; N, 13.21%.

Workup

  1. customThe toluene was removed
  2. temperaturethe temperature increased to 260° C.
  3. temperaturemaintained for two and one-half hours
  4. temperaturethe temperature increased to 290° C.
  5. temperaturemaintained for one and one-half hours
  6. customThe warm reaction mixture
  7. customwas precipitated in toluene
  8. washwashed in hot toluene
  9. customsubsequently dried at 110° C.
  10. customto afford 45.00 g (92% crude yield) of a red-tan powder, m.p. (DTA) 279° C. (broad)
  11. customThe solid was recrystallized from 40% aqueous ethanol

Sources & evidence

ORD record
ord-e0d2e37ec5984a58a11d2ea6443440ff
Source dataset
uspto-grants-1995_05
Patent number
US05412059

Reaction notes

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