反应详情

温度

25 °C

A solution of 1-tert-butyl-5-(5-chloro-isoxazol-3-yl)-1H-pyrazole-4-carboxylic acid ethyl ester (55.3 mg, 0.18 mmol) in absolute ethanol (0.93 mL, 0.2M) was treated with a 2M aqueous lithium hydroxide solution (0.18 mL, 0.37 mmol). The reaction was stirred at 25° C. for 1.5 h and then was heated to 100° C. for 1 h. At this time, the reaction was allowed to cool to 25° C. and was stirred at 25° C. overnight. At this time, the reaction was concentrated in vacuo. The residue was treated with water followed by acidification to pH=1 with a 1N aqueous hydrochloric acid solution. The resulting precipitate that formed was collected by filtration, washed with water and hexanes and dried in vacuo to afford 1-tert-butyl-5-(5-chloro-isoxazol-3-yl)-1H-pyrazole-4-carboxylic acid (38.7 mg, 77%) as an off-white solid.

1. temperaturewas heated to 100° C. for 1 h
2. temperatureto cool to 25° C.
3. stirringwas stirred at 25° C. overnight
4. concentrationAt this time, the reaction was concentrated in vacuo
5. additionThe residue was treated with water
6. customThe resulting precipitate that formed
7. filtrationwas collected by filtration
8. washwashed with water and hexanes
9. customdried in vacuo