Hydrochloric Acid → 3-(3-Chloro-5-trifluoromethylpyridin-2-yloxy)-5-methylpyrazole

Participants

Reaction Conditions

Reaction Steps

Potassium carbonate (7.60 g, 55.0 mmol) was added to a solution of 3-hydroxy-5-methylpyrazole (4.90 g, 50.0 mmol) and 2,3-dichloro-5-trifluoromethylpyridine (10.8 g, 50.0 mmol) in DMF (50 ml) at room temperature, and the mixture was stirred under heating at 60° C. for 4 hours. After completion of the reaction, the reaction mixture was poured into 2N hydrochloric acid (100 ml) and extracted with ethyl acetate (30 ml×3). An organic layer was washed with water, dried over anhydrous magnesium sulfate and filtered to remove a desiccant, and the solvent was distilled off from the filtrate under reduced pressure. The resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/2), to give a white solid of 3-(3-chloro-5-trifluoromethylpyridin-2-yloxy)-5-methylpyrazole (10.5 g, yield: 76.0%). mp: 93-95° C.; 1H-NMR (CDCl3, TMS, ppm): δ 2.32 (s, 3H), 5.90 (s, 1H), 7.98 (d, J=2.0 Hz, 1H), 8.33 (m, 1H), 10.80-11.60 (br s, 1H).

Provenance & Evidence