Sodium periodate → 4-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole-5-carbaldehyde

HRID 475094Notes

Reaction equation

HRID 475094 reaction equation
[CH3:1][O:2][C:3]1[C:11]2[N:10]=[CH:9][N:8]([CH:12]3[CH2:17][CH2:16][CH2:15][CH2:14][O:13]3)[C:7]=2[CH:6]=[CH:5][C:4]=1[CH:18]=CC1C=CC=CC=1.I([O-])(=O)(=O)=[O:27].[Na+]>O1CCOCC1.O.[Os](=O)(=O)(=O)=O>[CH3:1][O:2][C:3]1[C:11]2[N:10]=[CH:9][N:8]([CH:12]3[CH2:17][CH2:16][CH2:15][CH2:14][O:13]3)[C:7]=2[CH:6]=[CH:5][C:4]=1[CH:18]=[O:27]

Participants

6

Reactant 2

HCID 23667635Sodium periodateHCID 866946894-methoxy-5-styryl-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole

Product 1

HCID 866946904-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole-5-carbaldehydeYield 77.9%

Reagents, catalysts & solvents 3

HCID 30318Osmium TetroxideCatalystHCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

A 1 L three-necked round bottom flask fitted with an overhead stirrer was dried and cooled under a stream of nitrogen then charged with 4-methoxy-5-styryl-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole (25 g, 0.074 mol, 1.0 equiv.) in dioxane (250 mL) and water (80 mL). To this solution was added sodium periodate (36.77 g, 0.17 mol, 2.3 equiv.) and osmium tetroxide (15 mL, 4% aq. soln.) at 0° C., and the reaction mixture was stirred at RT overnight. The reaction mixture was quenched with ice cold water (1 L) and extracted with EtOAc (2×750 mL). The organic layers were combined, washed with brine (500 mL), dried (Na2SO4), filtered and concentrated in vacuo. The crude material was purified by SiO2 chromatography eluting with an EtOAc/hexane gradient (40-50% EtOAc) to afford 4-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole-5-carbaldehyde (15 g, 77%) as a pale yellow solid.

Workup

  1. customA 1 L three-necked round bottom flask fitted with an overhead stirrer
  2. customwas dried
  3. temperaturecooled under a stream of nitrogen
  4. customThe reaction mixture was quenched with ice cold water (1 L)
  5. extractionextracted with EtOAc (2×750 mL)
  6. washwashed with brine (500 mL)
  7. dry with materialdried (Na2SO4)
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo
  10. customThe crude material was purified by SiO2 chromatography
  11. washeluting with an EtOAc/hexane gradient (40-50% EtOAc)

Sources & evidence

ORD record
ord-ff448af7d35c42489ab686a9e2864299
Source dataset
uspto-grants-2014_01
Patent number
US08637537B2

Reaction notes

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