反应详情

温度

25 °C

A solution of 1-tert-butyl-5-(5-methyl-isoxazol-3-yl)-1H-pyrazole-4-carboxylic acid methyl ester (7.37 g, 26.59 mmol) in methanol (17.7 mL, 1.5M) cooled to 0° C. was treated dropwise with a 4N aqueous sodium hydroxide solution (13.3 mL, 53.15 mmol). The reaction was allowed to slowly warm to 25° C. The reaction was stirred at 25° C. over-night. At this time, the reaction was concentrated in vacuo to remove methanol. The residue was diluted with water (150 mL) and was then extracted with dichloromethane (3×150 mL). These organics were discarded. The aqueous layer was then acidified to pH=1 with a 2N aqueous hydrochloric acid solution. This solution was extracted with a 90/10 dichloromethane/methanol solution (3×150 mL). The combined organics were dried over sodium sulfate, filtered and concentrated in vacuo to afford 1-tert-butyl-5-(5-methyl-isoxazol-3-yl)-1H-pyrazole-4-carboxylic acid (5.42 g, 82%) as a brown solid. The material was used without further purification.

1. concentrationAt this time, the reaction was concentrated in vacuo
2. customto remove methanol
3. additionThe residue was diluted with water (150 mL)
4. extractionwas then extracted with dichloromethane (3×150 mL)
5. extractionThis solution was extracted with a 90/10 dichloromethane/methanol solution (3×150 mL)
6. dry with materialThe combined organics were dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo