反应详情

温度

100 °C

1H-Pyrazol-3-ylamine (9.5 g, 114 mmol) is added to a stirred solution of benzoyl isothiocyanate (19.6 g, 120 mmol) in DMF (100 ml) at room temperature. The solution is heated at 100° C. for 30 minutes, allowed to cool and poured onto water (1000 ml). The yellow suspension of 1-benzoyl-3-(1H-pyrazol-3-yl)-thiourea is removed by filtration and washed with water. This material is dissolved in 2M aqueous sodium hydroxide (120 ml) and the solution is heated at reflux for 30 minutes. After cooling to room temperature the solution is brought to pH 4 by addition of 3M aqueous HCl and extracted with ethyl acetate. The organic extract is dried (MgSO4) and concentrated to afford the titled compound which is removed by filtration and recrystallised from dichloromethane.

1. temperatureto cool
2. additionpoured onto water (1000 ml)
3. customis removed by filtration
4. washwashed with water
5. dissolutionThis material is dissolved in 2M aqueous sodium hydroxide (120 ml)
6. temperaturethe solution is heated
7. temperatureat reflux for 30 minutes
8. temperatureAfter cooling to room temperature the solution
9. additionis brought to pH 4 by addition of 3M aqueous HCl
10. extractionextracted with ethyl acetate
11. extractionThe organic extract
12. dry with materialis dried (MgSO4)
13. concentrationconcentrated