Ethyl orthoformate → ethyl 3-benzyl-3H-benzo[d]imidazole-5-carboxylate

HRID 1258936Notes

Reaction equation

HRID 1258936 reaction equation
[NH2:1][C:2]1[CH:12]=[CH:11][C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])=[CH:4][C:3]=1[NH:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.[CH:21](OCC)(OCC)OCC>C(O)C.Cl>[CH2:14]([N:13]1[C:3]2[CH:4]=[C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH:11]=[CH:12][C:2]=2[N:1]=[CH:21]1)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1

Participants

5

Reactant 2

HCID 31214Ethyl orthoformateHCID 58213838Ethyl 4-amino-3-(benzylamino)benzoate

Product 1

HCID 58213808ethyl 3-benzyl-3H-benzo[d]imidazole-5-carboxylateYield 48.1%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidCatalystHCID 702EthanolSolvent

Procedure

A solution of ethyl 4-amino-3-(benzylamino)benzoate (0.24 g, 0.89 mmol) and triethyl orthoformate (0.8 mL, 4.8 mmol) in ethanol (10 mL) and conc. HCl (7 drops) was heated to reflux for 24 hr. The solution was cooled to room temperature and concentrated, then diluted with ethyl acetate (100 mL) and washed with dilute aq. NaHCO3 (1×100 mL). Then organic layer was dried (MgSO4), filtered and then concentrated and the resulting residue was purified by flash chromatography (50% ethyl acetate/hexane then ethyl acetate) to provide 0.12 g (48%) of ethyl 3-benzyl-3H-benzo[d]imidazole-5-carboxylate as an off white solid.

Workup

  1. temperatureto reflux for 24 hr
  2. concentrationconcentrated
  3. additiondiluted with ethyl acetate (100 mL)
  4. washwashed with dilute aq. NaHCO3 (1×100 mL)
  5. dry with materialThen organic layer was dried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customthe resulting residue was purified by flash chromatography (50% ethyl acetate/hexane

Sources & evidence

ORD record
ord-36b8e473d8514497af10cbc53656e405
Source dataset
uspto-grants-2013_06
Patent number
US08466193B2

Reaction notes

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