Hydrochloric Acid → N-ethyl-3-(2-chloro-6-fluoro-4-trifluoromethylphenyloxy)-5-methylpyrazole-1-carboxamide

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Reaction Steps

Triethylamine (2.02 g, 20.0 mmol) and ethyl isocyanate (1.42 g, 20.0 mmol) were added to an ethyl acetate (50 mL) solution of 3-(2-chloro-6-fluoro-4-trifluoromethylphenyloxy)-5-methylpyrazole (5.33 g, 18.0 mmol), and the mixture was stirred at room temperature for 4 hours. After completion of the reaction, the reaction mixture was poured into 2 mol/L hydrochloric acid, followed by extraction with ethyl acetate (50 mL×3 times). The organic layer was washed with water and dried over anhydrous magnesium sulfate. Then, the desiccant was removed by filtering and the solvent was distilled off the filtrate under reduced pressure. The resultant crude product was purified with a silica gel column (ethyl acetate/hexane= 1/10) to give a white solid of N-ethyl-3-(2-chloro-6-fluoro-4-trifluoromethylphenyloxy)-5-methylpyrazole-1-carboxamide (5.37 g, yield: 81.6%). Melting point: 84˜86° C., 1H-NMR (Acetone-d6, Acetone, ppm): δ1.10 (t, J=7.2 Hz, 3H), 2.55 (d, J=0.9 Hz, 3H), 3.26 (dq, J=6.1 and 7.2 Hz, 2H), 5.98 (q, J=0.9 Hz, 1H), 7.39˜7.48 (brt, J=6.1 Hz, 1H), 7.75 (ddq, J=2.1 and JHF=0.7 and 9.7 Hz, 1H), 7.82 (dq, 1H, J=2.1 and JHF=0.7 Hz).

Provenance & Evidence