反应详情

Hydroxylamine hydrochloride (1.1 g.; 0.016 mol.) was added to a mixture of ethyl-2-(2',4'-dichlorobenzoyl)-3-dimethylaminopropenoate (4.74 g.; 0.015 mol.) and anhydrous sodium acetate (1.25 g.; 0.015 mol.) in 50 ml. of ether and 25 ml. of methanol at 25° C. An additional 25 ml. of methanol was added, and the resultant mixture was stirred for 30 minutes. The mixture was washed into a separatory funnel with 150 ml. of ether and the ether layer was washed free of salts with water. The ether layer was dried with magnesium sulfate, filtered, then concentrated to yield an oil which was crystallized from pentane to yield ethyl-5-(2',4'-dichlorophenyl)-4-isoxazolecarboxylate (1.88 g.; 44% yield) as tan crystals having a melting point of 82°-84° C. and the following analysis:

1. customat 25° C
2. washThe mixture was washed into a separatory funnel with 150 ml
3. washof ether and the ether layer was washed free of salts with water
4. dry with materialThe ether layer was dried with magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customto yield an oil which
8. customwas crystallized from pentane