Phenylboronic Acid → 4-iodo-2-methyl-1-phenyl-1H-imidazole

HRID 1898629Notes

Reaction equation

HRID 1898629 reaction equation
[I:1][C:2]1[N:3]=[C:4]([CH3:7])[NH:5][CH:6]=1.[C:8]1(B(O)O)[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1>C1COCC1.[Cu].CN(CCN(C)C)C>[I:1][C:2]1[N:3]=[C:4]([CH3:7])[N:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:6]=1.[I:1][C:2]1[N:3]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[C:4]([CH3:7])=[N:5][CH:6]=1

Participants

6

Reactant 2

HCID 66827Phenylboronic AcidHCID 178433060HCID 178433060, compound

Product 2

HCID 575166484-iodo-2-methyl-1-phenyl-1H-imidazoleYield 40%HCID 575166495-iodo-2-methyl-1-phenyl-1H-imidazoleYield 35%

Reagents, catalysts & solvents 2

HCID 86657874Copper TMEDACatalystHCID 8028TetrahydrofuranSolvent

Procedure

4-Iodo-2-methyl-1H-imidazole (1.0 g, 4.8 mmol) was dissolved in 30 mL of THF. Copper TMEDA catalyst (447 mg, 0.96 mmol, Aldrich) and then phenylboronic acid (0.41 g, 3.35 mmol) were added. Oxygen gas was bubbled into the reaction mixture for 20 min, then the mixture was stirred at room temperature for 90 min. An additional 0.21 g of phenylboronic acid was added followed by an additional 20 min of oxygen gas bubbling and 75 min of stirring at room temperature. An additional 0.21 g of phenylboronic acid was added followed by an additional 20 min of oxygen gas bubbling and then stirring at room temperature for 20 h. The reaction mixture was filtered through a bed of neutral alumina, concentrated and purified by silica gel chromatography (ethyl acetate/hexanes) to give 0.55 g (40%) of 4-iodo-2-methyl-1-phenyl-1H-imidazole ((M+H)+=285) and 0.47 g (35%) of 5-iodo-2-methyl-1-phenyl-1H-imidazole.

Workup

  1. customOxygen gas was bubbled into the reaction mixture for 20 min
  2. additionAn additional 0.21 g of phenylboronic acid was added
  3. waitfollowed by an additional 20 min of oxygen gas
  4. custombubbling and 75 min
  5. stirringof stirring at room temperature
  6. additionAn additional 0.21 g of phenylboronic acid was added
  7. waitfollowed by an additional 20 min of oxygen gas
  8. custombubbling
  9. stirringstirring at room temperature for 20 h
  10. filtrationThe reaction mixture was filtered through a bed of neutral alumina
  11. concentrationconcentrated
  12. custompurified by silica gel chromatography (ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-7da57c807df84a3fa07162b777d0698f
Source dataset
uspto-grants-2013_08
Patent number
US08518945B2

Reaction notes

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