反应详情

Potassium carbonate (3.52 g, 25.5 mmol) was added to a solution of 3-hydroxy-5-methylpyrazole (5.00 g, 51.0 mmol) in DMF (80 ml). Then, allylisocyanate (4.51 ml, 51.0 mmol) was added, and the mixture was stirred at room temperature for 6 hours. After completion of the reaction, the reaction mixture was poured into 1N hydrochloric acid and extracted with ethyl acetate (50 ml×2). An organic layer was washed with water (50 ml×3), dried over anhydrous magnesium sulfate and then filtered to remove a desiccant, and the solvent was distilled off from a filtrate under reduced pressure. The resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/3), to give a white solid of N-allyl-3-hydroxy-5-methylpyrazole-1-carboxamide (4.72 g, yield: 51.1%). mp: 80-83° C.; 1H-NMR (CDCl3, TMS, ppm): δ 2.55 (d, J=0.8 Hz, 3H), 3.97 (dddt, J=1.6, 1.6, 5.8 and 5.8 Hz, 2H), 5.19 (ddt, J=1.6, 2.7 and 10.3 Hz, 1H), 5.28 (ddt, J=1.6, 2.7 and 17.2 Hz, 1H), 5.63 (d, J=0.8 Hz, 1H), 5.90 (ddt, J=5.8, 10.3 and 17.2 Hz, 1H), 6.70 (m, 1H). (Hydroxy proton was not assigned.)

1. customAfter completion of the reaction
2. extractionextracted with ethyl acetate (50 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 a filtrate under reduced pressure
8. customThe resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/3)