反应详情

温度

25 °C

To a solution of 4-bromo-3-(difluoromethyl)-5-methyl-1H-pyrazole (1.40 g, 6.63 mmol) in chloroform (30.0 mL, 0.375 mol) was added p-toluenesulfonic acid monohydrate (0.13 g, 0.66 mol) at 0° C. Dihydropyran (0.91 mL, 0.010 mol) was added and stirred at 25° C. for 2 h. The reaction was extracted with ethyl acetate and the organic extracts were washed with NaHCO3, water, saturated NaCl, dried (MgSO4) and concentrated in vacuo. The compound was chromatographed on silica gel using 10% EtOAc/hexanes to give the desired product. 1H NMR (CDCl3): δ 6.51-6.78 (t, 1H), 5.31 (dd, 1H), 4.01 (m, 1H), 3.65 (m, 1H), 2.40 (m, 1H), 2.35 (s, 3H), 2.21 (m, 1H), 1.95 (m, 1H), 1.50-1.70 (m, 3H).

1. extractionThe reaction was extracted with ethyl acetate
2. washthe organic extracts were washed with NaHCO3, water, saturated NaCl
3. dry with materialdried (MgSO4)
4. concentrationconcentrated in vacuo
5. customThe compound was chromatographed on silica gel using 10% EtOAc/hexanes