反应详情

3-(4-Dimethylamino-phenyl)-3-oxo-propionitrile (3.262 gms.) is then suspended in 100 mL of anhydrous EtOH. This suspension is treated with 1.09 mL of anhydrous hydrazine, and subsequently is heated to refluxing temperature for 2 h. The reaction mixture is cooled to room temperature and stored in a −20° C. freezer overnight to yield a white crystalline precipitate. This precipitate is filtered and the filtrate is concentrated in vacuo. The residue from the evaporation is triturated with ethyl acetate to give additional precipitate. The combined precipitates are again triturated with ethyl acetate for 45 min. due to the presence of starting material in the initial precipitate. The solid material is collected by filtration providing the 5-(4-dimethylamino-phenyl)-2H-pyrazol-3-ylamine in the amount of 0.86 gms. (37% yield).

1. temperaturesubsequently is heated
2. temperatureto refluxing temperature for 2 h
3. customto yield a white crystalline precipitate
4. filtrationThis precipitate is filtered
5. concentrationthe filtrate is concentrated in vacuo
6. customThe residue from the evaporation
7. customis triturated with ethyl acetate
8. customto give additional precipitate
9. customThe combined precipitates
10. customare again triturated with ethyl acetate for 45 min. due to the presence of starting material in the initial precipitate
11. filtrationThe solid material is collected by filtration