Ethyl Acetate → Benzimidazole

HRID 2216188Notes

Reaction equation

HRID 2216188 reaction equation
C[C:2]1[CH:10]=[CH:9][C:5]2[NH:6][CH:7]=[N:8][C:4]=2[CH:3]=1.C1C(=O)N(I)C(=O)C1.CCOC(C)=O.C([O-])(O)=O.[Na+]>C(O)(C(F)(F)F)=O>[N:6]1[C:5]2[CH:9]=[CH:10][CH:2]=[CH:3][C:4]=2[NH:8][CH:7]=1

Participants

6

Reactant 4

HCID 8857Ethyl AcetateHCID 119795-MethylbenzimidazoleHCID 120273N-IodosuccinimideHCID 516892Sodium Bicarbonate

Product 1

HCID 5798BenzimidazoleYield 30%

Reagents, catalysts & solvents 1

HCID 6422Trifluoroacetic acidSolvent

Procedure

A solution of 5-methyl-1H-benzoimidazole (132 mg, 1.0 mmol) and NIS (248 mg, 1.10 mmol) in 1 mL of TFA was reflux for 1 hr and then cooled to RT. Treated with 30 mL of EtOAc, the mixture was neutralized with sat. NaHCO3 solution. The organic layer was washed with H2O (10 mL), brine (10 mL) and dried (Na2SO4). Removal of the solvent under reduced pressure followed by flash chromatography of the residue on silica gel (5% MeOH/CH2Cl2) gave 78 (30%) of product as a white solid: 1H-NMR (CDCl3; 400 MHz) δ 8.07 (d, 1H), 7.57 (br s, 1H), 7.22 (d, 1H, J=8.4 Hz), 2.59 (s, 3H). Mass spectrum (ESI, m/z): Calcd. for C8H7IN2, 259.0 (M+H), found 259.2.

Workup

  1. washThe organic layer was washed with H2O (10 mL), brine (10 mL)
  2. dry with materialdried (Na2SO4)
  3. customRemoval of the solvent under reduced pressure

Sources & evidence

ORD record
ord-ae11779b008848a096f58704df846d62
Source dataset
uspto-grants-2006_09
Patent number
US07109354B2

Reaction notes

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