Ethyl 6-nitro-1H-benzimidazole-2-carboxylate → 1H-Benzimidazole-2-carboxylic acid, 6-amino-, ethyl ester

HRID 56617Notes

Reaction equation

HRID 56617 reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[N:11]=[C:10]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[NH:9][C:8]=2[CH:17]=1)([O-])=O>C(O)C.[Pd]>[NH2:1][C:4]1[CH:5]=[CH:6][C:7]2[N:11]=[C:10]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[NH:9][C:8]=2[CH:17]=1

Participants

4

Reactant 1

HCID 57376767Ethyl 6-nitro-1H-benzimidazole-2-carboxylate

Product 1

HCID 450897201H-Benzimidazole-2-carboxylic acid, 6-amino-, ethyl ester

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

A solution of 1.9 g (8.1 mmol) of ethyl 6-nitro-1H-benzimidazole-2-carboxylate in 30 ml of ethanol was hydrogenated in the presence of 190 mg of palladium (10% on activated carbon) at RT and standard pressure for 3 h. The reaction mixture was then filtered through kieselguhr and the residue was washed with ethanol. The combined filtrates were concentrated under reduced pressure. The residue was dried under reduced pressure and then purified by flash chromatography (silica gel 50, mobile phase: dichloromethane/methanol 3-5%). Yield: 640 mg (39% of theory)

Workup

  1. filtrationThe reaction mixture was then filtered through kieselguhr
  2. washthe residue was washed with ethanol
  3. concentrationThe combined filtrates were concentrated under reduced pressure
  4. customThe residue was dried under reduced pressure
  5. custompurified by flash chromatography (silica gel 50, mobile phase: dichloromethane/methanol 3-5%)

Sources & evidence

ORD record
ord-e6ff972fde9c4477b3694df4ca56bc92
Source dataset
uspto-grants-2016_09
Patent number
US09434690B2

Reaction notes

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