反应详情

To a solution of 5-(3-butyl-5-formyl-isoxazol-4-ylmethoxy)-2-methyl-2H-pyrazole-3-carboxylic acid methyl ester (80 mg, 0.25 mmol) in methanol (4 mL) was added sodium borohydride (18.8 mg, 0.5 mmol) in portions over 3 min. Upon addition, the reaction became a clear light yellow solution containing a black precipitate. After stirring at room temperature for 1.5 h, the mixture was filtered over Celite® and the filter cake was washed with methanol. The filtrate was concentrated and the residue was portioned between 0.5M aqueous hydrochloric acid and ethyl acetate. The aqueous phase was extracted two times with ethyl acetate and the combined organic phases were washed with brine, dried over sodium sulfate and concentrated to a yellow oil. The crude material was purified by chromatography (silica, heptane:acetone 7.5:2.5) to afford the title compound (37 mg, 46%) as a dark brown oil. MS: m/e=324.3 [M+H]+.

1. additionUpon addition
2. additioncontaining a black precipitate
3. filtrationthe mixture was filtered over Celite®
4. washthe filter cake was washed with methanol
5. concentrationThe filtrate was concentrated
6. extractionThe aqueous phase was extracted two times with ethyl acetate
7. washthe combined organic phases were washed with brine
8. dry with materialdried over sodium sulfate
9. concentrationconcentrated to a yellow oil
10. customThe crude material was purified by chromatography (silica, heptane:acetone 7.5:2.5)