反应详情

To a solution of 1H-Pyrazole (10.0 mmol, 680 mg) in distilled dioxane (30 mL) were added KOtBu (11.0 mmol, 1.26 g), and followed by addition of 2,6-dibromopyridine (10.0 mmol, 2.37 g). The reaction mixture was refluxed for 48 hour, and then quenched with 5 mL of water. Solvent was removed under reduced pressure and water was added to the residue, then the mixture was extracted with DCM. The combined organic layers were washed with brine and dried over MgSO4. After solvent evaporation, the crude product was purified by column chromatography on silica gel (Hexanes:ethyl acetate=20:1 as eluent) to afford a white solid (2.01 g, 90%). 1H NMR (400 MHz, CDCl3, ppm): 8.53 (s, 1H), 7.92 (d, 1H, J=7.6 Hz), 7.73 (s, 1H), 7.67 (t, 1H, J=7.8 Hz), 7.35 (d, 1H, 7.6 Hz), 6.46 (s, 1H). 13C NMR (100 MHz, CDCl3, ppm): 162.72, 140.73, 139.91, 127.58, 125.25, 110.89, 108.23.

1. temperatureThe reaction mixture was refluxed for 48 hour
2. customquenched with 5 mL of water
3. customSolvent was removed under reduced pressure and water
4. additionwas added to the residue
5. extractionthe mixture was extracted with DCM
6. washThe combined organic layers were washed with brine
7. dry with materialdried over MgSO4
8. customAfter solvent evaporation
9. customthe crude product was purified by column chromatography on silica gel (Hexanes:ethyl acetate=20:1 as eluent)