Ethanol → 2-Benzyl-5-ethoxycarbonylbenzimidazole

HRID 321964Notes

Reaction equation

HRID 321964 reaction equation
[N+:1]([C:4]1[C:5](CC)=[C:6]([CH:10]=[CH:11][C:12]=1[NH:13][C:14](=O)[CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)[C:7]([O-:9])=[O:8])([O-])=O.[CH2:25](O)[CH3:26]>C(O)(=O)C>[CH2:15]([C:14]1[NH:1][C:4]2[CH:5]=[C:6]([C:7]([O:9][CH2:25][CH3:26])=[O:8])[CH:10]=[CH:11][C:12]=2[N:13]=1)[C:16]1[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1

Participants

4

Reactant 2

HCID 702EthanolHCID 701409133-Nitro-4-phenylacetylamino-ethylbenzoate

Product 1

HCID 102213332-Benzyl-5-ethoxycarbonylbenzimidazole

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A mixture of 3-nitro-4-phenylacetylamino-ethylbenzoate (3.60 g), ethanol (47 ml), acetic acid (23 ml) and reduced iron (6.4 g) is refluxed for four hours. Solids are separated through filtration and the filtrate is concentrated. Ethanol (50 ml) and 35% hydrochloric acid (5 g) are added to the residue and the solution is refluxed for 40 hours. The solution is neutralized with sodium bicarbonate and chloroform extraction is performed. The organic layer is concentrated under reduced pressure and then purified using silica gel column chromatography. Thus, 2-benzyl-5-ethoxycarbonylbenzimidazole (2.30 g) is obtained. 1H-NMR (CDCl3, δ): 1.39 (3H, t, J=7.1 Hz), 4.26 (2H, s), 4.37 (2H, q, J=7.1 Hz), 7.22-7.36 (5H, m), 7.50 (1H, d, J=8.6 Hz), 7.94 (1H, dd, J=1.5 and 8.6 Hz), 8.23 (1H, d, J=1.3 Hz).

Workup

  1. temperatureis refluxed for four hours
  2. customSolids are separated through filtration
  3. concentrationthe filtrate is concentrated
  4. additionEthanol (50 ml) and 35% hydrochloric acid (5 g) are added to the residue
  5. temperaturethe solution is refluxed for 40 hours
  6. extractionThe solution is neutralized with sodium bicarbonate and chloroform extraction
  7. concentrationThe organic layer is concentrated under reduced pressure
  8. custompurified

Sources & evidence

ORD record
ord-272485b9e0474238a166b526b3f48b61
Source dataset
uspto-grants-2001_04
Patent number
US06211177B1

Reaction notes

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