反应详情

To a stirred solution of (2S,4R)-2-(2-bromo-phenylcarbamoyl)-4-tert-butoxy-pyrrolidine-1-carboxylic acid benzyl ester (900 mg, 1.89 mmol) in DME (20 mL) at 25° C. in a sealed tube were added CuI (36 mg, 0.19 mmol), 1,10-phenanthraline (68 mg, 0.38 mmol), and Cs2CO3 (1.847 g, 5.68 mmol). The reaction mixture was refluxed for 14 h. After completion of reaction, water was added, and the mixture was then extracted with dichloromethane. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude was then purified by column chromatography to give (2S,4R)-2-benzooxazol-2-yl-4-tert-butoxy-pyrrolidine-1-carboxylic acid benzyl ester (430 mg, 57.5% yield) as a yellowish liquid. MS calcd. for C23H27N2O4 [(M+H)+] 395, obsd. 395.

1. temperatureThe reaction mixture was refluxed for 14 h
2. additionwas added
3. extractionthe mixture was then extracted with dichloromethane
4. washThe organic layer was washed with brine
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe crude was then purified by column chromatography