反应详情

Potassium hydrogencarbonate (0.15 g, 1.5 mmol) was added to a solution of 3-(3-fluoro-4-nitrophenyloxy)-5-methylpyrazole (0.36 g, 1.5 mmol) in ethanol (5 ml), and the mixture was refluxed under heating for 10 hours. After completion of the reaction, the reaction mixture was poured into water (10 ml) and extracted with ethyl acetate (10 ml×2), dried over anhydrous magnesium sulfate and filtered to remove magnesium sulfate, 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=1/5), to give a yellow solid of 3-(3-ethoxy-4-nitrophenyloxy)-5-methylpyrazole (0.17 g, yield: 42.3%). mp: 123-124° C.; 1H-NMR (CDCl3, TMS, ppm): δ 1.47 (t, J=7.0 Hz, 3H), 2.33 (d, J=0.5 Hz, 3H), 4.13 (q, J=7.0 Hz, 2H), 5.73 (d, J=0.5 Hz, 1H), 6.68 (dd, J=2.5 and 9.1 Hz, 1H), 6.81 (d, J=2.5 Hz, 1H), 7.91 (d, J=9.1 Hz, 1H), 9.53 (br s, 1H).

1. temperaturethe mixture was refluxed
2. temperatureunder heating for 10 hours
3. customAfter completion of the reaction
4. extractionextracted with ethyl acetate (10 ml×2)
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationfiltered
7. customto remove magnesium sulfate
8. distillationthe solvent was distilled off from the filtrate under reduced pressure
9. customThe resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/5)