Benzimidazole → 1H-benzimidazol-1-ylacetonitrile

HRID 1455610Notes

Reaction equation

HRID 1455610 reaction equation
[N:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[NH:3][CH:2]=1.CC(C)([O-])C.[K+].Br[CH2:17][C:18]#[N:19]>CN(C)C=O>[N:1]1([CH2:17][C:18]#[N:19])[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[CH:2]1

Participants

5

Reactant 3

HCID 5798BenzimidazoleHCID 11534BromoacetonitrileHCID 23665647Potassium tert-butoxide

Product 1

HCID 47367691H-benzimidazol-1-ylacetonitrileYield 89.8%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To an ice cooled solution of benzimidazole (10 g, 0.085 mol) in dry N,N-dimethylformamide (500 mL) was added potassium tert-butoxide (9.6 g, 0.085 mol) portionwise. The mixture was stirred at room temperature for 1 h then bromoacetonitrile (6 mL, 0.086 mol) was added in one portion and stirred for 3 h. The mixture was then quenched with solid carbon dioxide followed by water and the organics separated. The organics were washed further with water (100 mL×5), and brine (100 mL×1) combined and dried (Na2SO4), filtered and evaporated to dryness. The residue was passed through a silica gel column eluting with dichloromethane:ethanol (1% up to 6% ethanol) to give a yellow solid (12 g, 89%). 1H NMR (400 MHz, CDCl3) δ ppm 5.08 (2H, s), 7.36-7.43 (2H, m), 7.47 (1H, d, J=7.4 Hz), 7.85 (1H, d, J=7.2 Hz), 7.93 (1H, s).

Workup

  1. stirringstirred for 3 h
  2. customThe mixture was then quenched with solid carbon dioxide
  3. washThe organics were washed further with water (100 mL×5), and brine (100 mL×1)
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. customevaporated to dryness
  7. washeluting with dichloromethane

Sources & evidence

ORD record
ord-c9a50ebee3ba4f32ae181bb6afd861a0
Source dataset
uspto-grants-2009_01
Patent number
US07482469B2

Reaction notes

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