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

Participants

Reaction Steps

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.

Provenance & Evidence