反应详情

(5RS)-3-(4-Bromophenyl)-5-hydroxymethyl-4,5-dihydro-isoxazole (3.07 g, 12 mM), triphenylphosphine (3.78 g, 14.4 mM) and 3-hydroxyisoxazole (1.02 g, 12 mM) were dissolved in anhydrous tetrahydrofuran (50 ml), cooled to 0° with stirring under nitrogen, and treated with diisopropylazodicarboxylate (2.71 g, 13.4 mM). Stirring was continued for 18 hours, and the mixture evaporated to dryness. The residue was chromatographed on a 90 g Biotage silica column, eluting with 25% ethyl acetate in isohexane, appropriate fractions combined, and chromatographed again on a 40 g Biotage silica column, eluting with 5% methanol in dichloromethane. Appropriate fractions were combined to give the desired product (2.15 g). MS (ESP): 323 (MH+) for C13H11BrN2O3

1. temperaturecooled to 0°
2. stirringStirring
3. customthe mixture evaporated to dryness
4. customThe residue was chromatographed on a 90 g Biotage silica column
5. washeluting with 25% ethyl acetate in isohexane, appropriate fractions
6. customchromatographed again on a 40 g Biotage silica column
7. washeluting with 5% methanol in dichloromethane