Selenium Dioxide → 1-Phenyl-1H-benzimidazole-2-carboxaldehyde

HRID 2231240Notes

Reaction equation

HRID 2231240 reaction equation
[C:1]1([N:7]2[C:11]3[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=3[N:9]=[C:8]2[CH3:16])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[Se](=O)=[O:18]>O1CCOCC1>[C:1]1([N:7]2[C:11]3[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=3[N:9]=[C:8]2[CH:16]=[O:18])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

4

Reactant 2

HCID 24007Selenium DioxideHCID 6394272-methyl-1-phenyl-1H-benzimidazole

Product 1

HCID 150720641-Phenyl-1H-benzimidazole-2-carboxaldehydeYield 50.2%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

To a solution of 5.0 g (0.024 mole) of 1-phenyl-2methylbenzimidazole in 200 ml of dioxane was added 2.66 g (0.024 mole) of selenium dioxide and the reaction heated to reflux for 7 hours. The solids were filtered and the filtrate concentrated to a brown oil. The residue was chromatographed on 200 g of silica gel using 7% ethyl acetate in chloroform as the eluent to give 2.68 g of purified product.

Workup

  1. temperaturethe reaction heated
  2. temperatureto reflux for 7 hours
  3. filtrationThe solids were filtered
  4. concentrationthe filtrate concentrated to a brown oil
  5. customThe residue was chromatographed on 200 g of silica gel using 7% ethyl acetate in chloroform as the eluent

Sources & evidence

ORD record
ord-1bd5e0b8009141dc82fbf207db642446
Source dataset
uspto-grants-1988_11
Patent number
US04782050

Reaction notes

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