Potassium Phosphate, Tribasic → 3-bromo-5-(2-chloro-4-fluorophenyl)-1-methyl-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

A mixture of 3,5-dibromo-1-methyl-1H-pyrazole (i.e. the product of Step B) (2.00 g, 8.33 mmol) in toluene (40 mL) was sparged with a stream of argon for 45 minutes, and then 2-chloro-4-fluorophenylboronic acid (1.59 g, 9.11 mmol), potassium phosphate tribasic (5.30 g, 25.0 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.48 g, 0.41 mmol) were added. The reaction mixture was heated at 90° C. for 3 h, and then cooled to room temperature and diluted with ethyl acetate (250 mL). The mixture was washed with water (25 mL) and saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated under reduced pressure. The resulting material was purified by silica gel chromatography (5 to 40% gradient of ethyl acetate in hexanes as eluant) to provide the title compound as a white solid (620 mg).

Provenance & Evidence