Ethyl Acetate → 4-Iodo-5-methyl-1H-benzoimidazole

HRID 723235Notes

Reaction equation

HRID 723235 reaction equation
[CH3:1][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:18])C(=O)C1.CCOC(C)=O.C([O-])(O)=O.[Na+]>C(O)(C(F)(F)F)=O>[I:18][C:3]1[C:4]2[N:8]=[CH:7][NH:6][C:5]=2[CH:9]=[CH:10][C:2]=1[CH3:1]

Participants

6

Reactant 4

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

Product 1

HCID 218863944-Iodo-5-methyl-1H-benzoimidazoleYield 30.2%

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 mg (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-ac87af7ff7c34219a70567ee909e8579
Source dataset
uspto-grants-2006_11
Patent number
US07138530B2

Reaction notes

Loading…