反应详情

Potassium carbonate (0.83 g, 6.0 mmol) and methyl isocyanate (0.29 g, 5.0 mmol) were added to a solution of 5-ethyl-3-(4-nitro-2-trifluoromethylphenyloxy)pyrazole (1.81 g, 6.0 mmol) in ethyl acetate (15 ml), and the mixture was stirred at room temperature overnight. After completion of the reaction, the reaction mixture was poured into 2N hydrochloric acid and extracted with diethyl ether (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=1/7), to give a yellow solid of N-methyl-5-ethyl-3-(4-nitro-2-trifluoromethylphenyloxy)pyrazole-1-carboxamide (1.42 g, yield: 79.3%). mp: 97-100° C.; 1H-NMR (CDCl3, TMS, ppm): δ 1.30 (t, J=7.5 Hz, 3H), 2.95 (d, J=5.0 Hz, 3H), 3.12 (q, J=7.5H, 2H), 5.93 (s, 1H), 6.75-7.00 (m, 1H), 7.45 (d, J=9.2 Hz, 1H), 8.41 (dd, J=2.7 and 9.2 Hz, 1H), 8.60 (d, J=2.7 Hz, 1H).

1. customAfter completion of the reaction
2. extractionextracted with diethyl ether (20 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=1/7)