反应详情

A round bottom flask with magnetic stirrer was charged with 3-methyl-isoxazole-5-carboxylic acid ethyl ester (900 mg, 5.8 mmol) in tetrahydrofuran (2.0 mL). To the reaction was added a solution of sodium hydroxide (465 mg, 11.6 mmol) in water (2 mL), followed by methanol (4 mL). The reaction was stirred at room temperature for 18-20 hours under an argon atmosphere. The reaction was transferred to a separatory funnel and the pH adjusted to 2 via addition of 1N hydrochloric acid. The mixture was extracted with ethyl acetate (3×35 mL) and the combined extractions were washed with brine (1×50 mL), dried over magnesium sulfate, and filtered. The filtrate was concentrated in vacuo to yield 3-methyl-isoxazole-5-carboxylic acid as a white solid (660 mg, 90%). The solid was used without purification in the next reaction.

1. customThe reaction was transferred to a separatory funnel
2. extractionThe mixture was extracted with ethyl acetate (3×35 mL)
3. extractionthe combined extractions
4. washwere washed with brine (1×50 mL)
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationThe filtrate was concentrated in vacuo