p-Toluenesulfonic acid → 2-(2-Methylphenyl)-5-nitrobenzimidazole

HRID 2243103Notes

Reaction equation

HRID 2243103 reaction equation
[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[CH:7][C:3]=1[C:4](Cl)=O.[NH2:11][C:12]1[CH:18]=[C:17]([N+:19]([O-:21])=[O:20])[CH:16]=[CH:15][C:13]=1[NH2:14].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]1[NH:11][C:12]2[CH:18]=[C:17]([N+:19]([O-:21])=[O:20])[CH:16]=[CH:15][C:13]=2[N:14]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 702762-Methylbenzoyl chlorideHCID 51117914-Nitro-1,2-phenylenediamine

Product 1

HCID 232750332-(2-Methylphenyl)-5-nitrobenzimidazole

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

2-Methylbenzoyl chloride (4.1 g, 0.027 mol) is added to 2-amino-4-nitroaniline (4 g, 0.025 mol) in toluene (100 ml), and the mixture is refluxed for 24 hours. para-Toluenesulfonic acid (1.0 g) is added, the mixture is refluxed for 36 hours and concentrated, and the residue is taken up in ethyl acetate. The solution is washed with NaHCO3 and then with water. The resulting solution is dried and concentrated, and the solid obtained is recrystallized from isopropyl ether. Yield: 3.1 g (48%); Rf (7/3 toluene/ethyl acetate): 0.58; 1H-NMR (d6-DMSO): 8.5 (d, 1H); 8.1 (dd, 1H); 7.7 (m, 2H); 7.4 (m, 3H); 2.6 (s, 3H).

Workup

  1. temperaturethe mixture is refluxed for 24 hours
  2. temperaturethe mixture is refluxed for 36 hours
  3. concentrationconcentrated
  4. washThe solution is washed with NaHCO3
  5. customThe resulting solution is dried
  6. concentrationconcentrated
  7. customthe solid obtained
  8. customis recrystallized from isopropyl ether

Sources & evidence

ORD record
ord-8ec235f234744934b39064810feb0f7a
Source dataset
uspto-grants-2010_03
Patent number
US07674809B2

Reaction notes

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