反应详情

温度

0 °C

To a stirred solution of diisopropylamine (0.441 mL, 3.10 mmol) in anhydrous THF (2 mL) was added n-BuLi (1.239 mL, 3.10 mmol) (2.5M solution in hexanes) dropwise at 0° C. under nitrogen. The pale yellow solution was then stirred at the same temperature for 20 min. before a solution of (E)-5-vinyl-2,3-dihydro-1H-inden-1-one oxime (Preparation 87B, 0.249 g, 1.438 mmol) in anhydrous THF (1 mL) was added dropwise at 0° C. under nitrogen. The mixture was stirred at 0° C. for 1 h and then a solution of methyl 5-phenyl-4-(trifluoromethyl)isoxazole-3-carboxylate (Intermediate 1-5, 0.3 g, 1.106 mmol) in anhydrous THF (1 mL) was added dropwise at 0° C. The mixture was stirred at 0° C. for 70 min before being quenched with saturated aqueous ammonium chloride solution (3 mL) and water (3 mL). The mixture was extracted with EtOAc (2×30 mL). The EtOAc extracts were washed with brine (20 mL), dried over sodium sulfate and concentrated to yield a brown foamy solid. Flash chromatography purification (12 g silica gel column, 10→50% ethyl acetate in n-heptane) afforded 3-(5-phenyl-4-(trifluoromethyl)isoxazol-3-yl)-6-vinyl-3a,4-dihydro-3H-indeno[1,2-c]isoxazol-3-ol as a brown solid.

1. additionwas added dropwise at 0° C. under nitrogen
2. stirringThe mixture was stirred at 0° C. for 70 min
3. custombefore being quenched with saturated aqueous ammonium chloride solution (3 mL) and water (3 mL)
4. extractionThe mixture was extracted with EtOAc (2×30 mL)
5. washThe EtOAc extracts were washed with brine (20 mL)
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated
8. customto yield a brown foamy solid
9. customFlash chromatography purification (12 g silica gel column, 10→50% ethyl acetate in n-heptane)