反应详情

To a stirred solution of 7 g of 3-amino-5-(1,1-dimethylethyl)isoxazole and 5.05 g triethylamine dissolved in 100 ml ethyl acetate was added 7.75 g of 2-methyl-4-chlorobutyric acid chloride dropwise. The mixture was stirred for about 16 hours at room temperature and the precipitated salt was collected by filtration and washed with ethyl acetate. The filtrate was concentrated under reduced pressure and the residue was chromatographed over silica gel while eluting with a 1:1 (v/v) mixture of toluene:diethyl ether. Fractions containing the major component as indicated by thin layer chromatography were combined and concentrated under vacuum to provide 7 g of 4-chloro-N-[5-(1,1-dimethylethyl)-3-isoxazolyl]-2-methylbutanamide. Yield 54%. This material was used in the following reaction without additional purification.

1. filtrationthe precipitated salt was collected by filtration
2. washwashed with ethyl acetate
3. concentrationThe filtrate was concentrated under reduced pressure
4. customthe residue was chromatographed over silica gel
5. washwhile eluting with a 1:1 (v/v) mixture of toluene
6. additionFractions containing the major component
7. concentrationconcentrated under vacuum