反应详情

温度

60 °C

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-fluoro-5-nitrobenzotrifluoride (10.5 g, 50.0 mmol) in DMF (50 ml), 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 (50 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=1/3), to give a yellowish viscous substance of 5-methyl-3-(4-nitro-2-trifluoromethylphenyloxy)pyrazole (8.70 g, yield: 60.6%). 1H-NMR (CDCl3, TMS, ppm): δ 2.30 (d, J=0.5 Hz, 3H), 5.78 (d, J=0.5 Hz, 1H), 7.31 (d, J=9.2 Hz, 1H), 8.31 (dd, J=2.7 and 9.2 Hz, 1H), 8.57 (d, J=2.7 Hz, 1H), 10.05-10.50 (br s, 1H).

1. customAfter completion of the reaction
2. extractionextracted with ethyl acetate (50 ml×3)
3. washAn organic layer was washed with water
4. dry with materialdried over anhydrous magnesium sulfate
5. filtrationfiltered
6. customto remove a desiccant, and the solvent
7. distillationwas distilled off from the filtrate under reduced pressure
8. customThe resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/3)