反应详情

To a suspension of ethyl 5-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylate (12.1 g, 48.5 mmol) in ethanol (250 ml) was added a solution of lithium hydroxide (5.8 g, 242 mmol) in water (100 ml). The mixture was stirred at reflux for 2.5 hours. It was allowed to cool and concentrated to 50% of its volume before 5M hydrochloric acid (47 ml) was added. After stirring for 15 minutes, the resulting white solid was filtered off and further 5M hydrochloric acid (3 ml) was added to the filtrate and the resulting solid was filtered and the combined solids were washed with water and diethyl ether and then dried under vacuum to give the title compound (10.27 g).

1. temperatureat reflux for 2.5 hours
2. temperatureto cool
3. concentrationconcentrated to 50% of its volume before 5M hydrochloric acid (47 ml)
4. additionwas added
5. stirringAfter stirring for 15 minutes
6. filtrationthe resulting white solid was filtered off
7. additionfurther 5M hydrochloric acid (3 ml) was added to the filtrate
8. filtrationthe resulting solid was filtered
9. washthe combined solids were washed with water and diethyl ether
10. customdried under vacuum