O-Phenylenediamine → 2-Pentyl-1H-benzimidazole

HRID 653696Notes

Reaction equation

HRID 653696 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].C(N(CC)CC)C.[C:16](Cl)(=O)[CH2:17][CH2:18][CH2:19][CH2:20][CH3:21]>C(Cl)Cl>[CH2:17]([C:16]1[NH:7][C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][C:1]=2[N:8]=1)[CH2:18][CH2:19][CH2:20][CH3:21]

Participants

5

Reactant 3

HCID 7243O-PhenylenediamineHCID 8471TriethylamineHCID 67340Hexanoyl chloride

Product 1

HCID 221232-Pentyl-1H-benzimidazoleYield 47%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 0-phenylenediamine (2.2 g) and triethylamine (2.0 g) in methylene chloride (20 ml) was added dropwise caproyl chloride (2.3 g) with stirring under ice-cooling. The mixture was stirred for 3 hours at room temperature, washed with a saturated aqueous sodium bicarbonate and water, then dried. The solvent was evaporated. To the residue was added 3N-HCl, and the mixture was heated for 1.5 hour under reflux. The reaction mixture was made basic with 6N NaOH. Then precipitating crystals were recrystallized from ethyl acetate-hexane to give colorless needles (1.5 g, 47%), m.p. 161°-162° C.

Workup

  1. temperaturecooling
  2. stirringThe mixture was stirred for 3 hours at room temperature
  3. washwashed with a saturated aqueous sodium bicarbonate and water
  4. customdried
  5. customThe solvent was evaporated
  6. additionTo the residue was added 3N-HCl
  7. temperaturethe mixture was heated for 1.5 hour
  8. temperatureunder reflux
  9. customThen precipitating crystals
  10. customwere recrystallized from ethyl acetate-hexane

Sources & evidence

ORD record
ord-d72d7967d955422e83f4638562d5580f
Source dataset
uspto-grants-1992_07
Patent number
US05128356

Reaction notes

Loading…