Hydrochloric Acid → 1-Methyl-3-bromo-5-(4-trifluoromethylphenyl)pyrazole

Participants

Reaction Steps

A solution of 1-methyl-3-bromo-5-(nonafluorobutanesulfonyloxy)pyrazole from Example 69 Step 2 (0.16 g, 0.35 mmol), 4-trifluoromethylbenzeneboronic acid (0.07 g, 0.36 mmol), tetrakis(triphenylphosphine) palladium (0) (0.04 g, 10 mol %), sodium carbonate (0.04 g, 0.38 mmol) in dry N,N-dimethylformamide (2 mL) was stirred under nitrogen at 40° C. for 18 hours. The cooled reaction mixture was poured into 1M hydrochloric acid (10 ml) and extracted with diethyl ether (2×10 mL). The combined organic layers were dried (Na2SO4) and concentrated to give an oil which was purified by flash column chromatography on silica eluting with 5% ethyl acetate-isohexane to give 1-methyl-3-bromo-5-(4-trifluoromethylphenyl)pyrazole as a white solid (0.06 g, 56%).

Provenance & Evidence