反应详情

温度

70 °C

Potassium carbonate (2.23 g, 16.1 mmol) was added to a solution of 3-hydroxy-5-methylpyrazole (3.16 g, 32.2 mmol) and 5-fluoro-2-nitrotoluene (5.00 g, 32.2 mmol) in DMF (50 ml), and the mixture was stirred at 70° C. for 3 hours. After completion of the reaction, a reaction mixture was poured into 2N hydrochloric acid (50 ml) and extracted with ethyl acetate (30 ml×2). An organic layer was washed with water (50 ml×3), 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 solid of 5-methyl-3-(4-nitro-3-methylphenyloxy)pyrazole (2.51 g, yield: 27.8%). mp: 114-117° C.; 1H-NMR (CDCl3, TMS, ppm): δ 2.30 (d, J=0.5 Hz, 3H), 2.61 (s, 3H), 5.72 (d, J=0.5 Hz, 1H), 6.98-7.04 (m, 2H), 8.05 (d, J=9.8 Hz, 1H), 10.12 (br s, 1H).

1. customAfter completion of the reaction
2. extractionextracted with ethyl acetate (30 ml×2)
3. washAn organic layer was washed with water (50 ml×3)
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)