反应详情

温度

0 °C

5-Methylisoxazole-3-carbonitrile (1.0 g, 1 mmol) was dissolved in THF. Ti(Oi-Pr) 4 (1.2 mmol) was added dropwise over a period of 5-10 min and the reaction mixture was stirred at r.t for 15 min. It was then cooled down to 0° C. and EtMgBr (2.5 mmol) was added dropwise over a period of 10-15 min. It was stirred at 0° C. for 15 min. and then stirred at rt for 1 hr. The mixture was cooled again to 0° C. and BF3OEt2 (2 mmol) was added dropwise over a period of 5-10 min at 0° C. After the mixture was stirred for 10 min at 0° C. and 1 hr at rt, 1 N NaOH was added at 0° C. DCM was added to the reaction mixture which was then stirred for 5-10 min. This alkaline solution was filtered through CELITE® and washed with DCM. The organic layer was concentrated and residue purified by flash chromatography on silica gel using 10% chloroform/methanol. Yield: 0.6 g 1H NMR (400 MHz, CDCl3): δ 0.96-1.05 (m, 4H), 2.36 (s, 3H), 5.59 (s, 1H). LCMS: (ES+) m/z observed 138.7.

1. stirringIt was stirred at 0° C. for 15 min.
2. stirringstirred at rt for 1 hr
3. temperatureThe mixture was cooled again to 0° C.
4. additionBF3OEt2 (2 mmol) was added dropwise over a period of 5-10 min at 0° C
5. stirringAfter the mixture was stirred for 10 min at 0° C. and 1 hr at rt
6. stirringwas then stirred for 5-10 min
7. filtrationThis alkaline solution was filtered through CELITE®
8. washwashed with DCM
9. concentrationThe organic layer was concentrated
10. customresidue purified by flash chromatography on silica gel using 10% chloroform/methanol