Iodine → 3-(2,5-dimethylpyrrol-1-yl)-5-iodo-1-phenyl-1H-pyrazole

Participants

Reaction Steps

To a solution of 3-(2,5-dimethylpyrrol-1-yl)-1-phenyl-1H-pyrazole (14.6 g) in tetrahydrofuran (80 ml) cooled to −78° C. was added n-butyllithium (1.6M solution in n-hexane, 24 ml) over 5 minutes, and then the mixture was stirred for 1 hour. To this mixture was added a solution of iodine (15.7 g) in tetrahydrofuran (30 ml) over 10 minutes, and the mixture was stirred for additional 1.5 hours. To this mixture were sequentially added water (5 ml) and a saturated aqueous solution of sodium hydrogen sulfite (30 ml), and then the mixture was warmed to 0° C., and additional water (150 ml) was added thereto, and the mixture was stirred at room temperature for 1 hour. A precipitated solid was collected by filtration, washed with water and a small amount of methanol, and dried under reduced pressure to give the titled compound (13.0 g).

Provenance & Evidence