反应详情

Trichloromethyl chloroformate (0.59 g, 3.0 mmol) was added to a solution of 5-methyl-3-(3-trifluoromethylphenyloxy)pyrazole (0.48 g, 2.0 mmol) in ethyl acetate (10 ml) at 0° C., and while the mixture was allowed to have room temperature gradually, the mixture was further stirred at room temperature for 3 hours. To the reaction mixture were added O-ethylhydroxylamine hydrochloride (0.98 g, 10.0 mmol) and triethylamine (0.61 g, 6.0 mmol), and the resulting mixture was refluxed under heating. After completion of the reaction, the reaction mixture was poured into ice water, and the mixture was extracted with ethyl acetate (20 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=1/10), to give a yellowish viscous substance of N-ethoxy-5-methyl-3-(3-trifluoromethylphenyloxy)pyrazole-1-carboxamide (0.30 g, yield: 45.4%). 1H-NMR (CDCl3, TMS, ppm): δ 1.31 (t, J=7.0 Hz, 3H), 2.61 (d, J=0.8 Hz, 3H), 4.05 (q, J=7.0 Hz, 2H), 5.78 (q, J=0.8 Hz, 1H), 7.33-7.37 (m, 1H), 7.42-7.50 (m, 3H), 9.25 (br s, 1H).

1. customto have room temperature
2. temperaturethe resulting mixture was refluxed
3. temperatureunder heating
4. customAfter completion of the reaction
5. extractionthe mixture was extracted with ethyl acetate (20 ml×3)
6. washAn organic layer was washed with water
7. dry with materialdried over anhydrous magnesium sulfate
8. filtrationfiltered
9. customto remove a desiccant, and the solvent
10. distillationwas distilled off from the filtrate under reduced pressure
11. customThe resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/10)