反应详情

Starting material 1-(5-bromo-2-chloropyridin-3-yl)ethanone (5.8 g, 24.7 mmol) and 100 ml anhydrous hydrazine was charged into 500 ml round bottom flask and the resulting mixture was allowed to stir at room temperature for overnight. After removing the excess hydrazine via rotatory evaporation under reduced pressure, the remaining residue was diluted with distilled water and solid was appeared. After filtering the water, the resulting solid was taken up in ethylacetate and saturated aqueous sodium bicarbonate and was extracted by ethylacetate twice. The combined organic layer was washed with water and brine and dried over sodium sulfate. The crude product was eluted through a short silica gel column (3 inch in length) with ethylacetate as a white solid (4.0 g, y=77%).

1. additionwas charged into 500 ml round bottom flask
2. customAfter removing the excess hydrazine
3. customvia rotatory evaporation under reduced pressure
4. additionthe remaining residue was diluted with distilled water and solid
5. filtrationAfter filtering the water
6. extractionsaturated aqueous sodium bicarbonate and was extracted by ethylacetate twice
7. washThe combined organic layer was washed with water and brine
8. dry with materialdried over sodium sulfate
9. washThe crude product was eluted through a short silica gel column (3 inch in length) with ethylacetate as a white solid (4.0 g, y=77%)