Ammonia → 3-(2,5-dimethylpyrrol-1-yl)-1-(3-fluorophenyl)-5-iodo-1H-pyrazole

Participants

Reaction Steps

To a solution of 3-(2,5-dimethylpyrrol-1-yl)-1-(3-fluorophenyl)-1H-pyrazole (10.4 g) in tetrahydrofuran (100 ml) cooled to −78° C. was added n-butyllithium (1.6M solution in n-hexane, 31 ml) over 10 minutes, and then the mixture was stirred for 30 minutes. To the mixture was added dropwise a solution of iodine (12.4 g) in tetrahydrofuran (20 ml) over 10 minutes, and the mixture was stirred for additional 30 minutes. To the mixture were sequentially added a 20 wt % aqueous solution of sodium thiosulfate and a saturated aqueous ammonia, and then the mixture was warmed to room temperature, and extracted with ethyl acetate. The separated organic layer was washed with a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. To the resulting residue was added a mixed solvent of n-hexane/ethyl acetate (2/1), and the mixture was stirred. The insoluble substance was collected by filtration, and dried under reduced pressure to give the titled compound (4.5 g).

Provenance & Evidence