反应详情

4-(R)-[1-(tert-butoxycarbonylamino)cyclopropyl]-1-[1-(S)-phenylethyl]pyrrolidin-2-one (10.4 g, 30.2 mmol) was dissolved in anhydrous tetrahydrofuran (100 ml) and a 1.0M borane-tetrahydrofuran complex/tetrahydrofuran solution (90.7 ml, 90.7 mmol) was added dropwise gradually thereto under a nitrogen atmosphere while cooling with ice. After completion of dripping, it was stirred for 16 hours under the condition of from ice-cooling to room temperature. After slowly adding an aqueous solution (100 ml) of potassium carbonate (25.0 g, 181 mmol) to the reaction solution while cooling with ice, it was heated under reflux was for 1.5 hours. After letting the reaction solution cool, it was extracted with ethyl acetate (10 ml×2) and then washed with saturated saline solution (100 ml) The organic layer was then dried over anhydrous sodium sulfate, and after filtering, the filtrate was concentrated under a reduced pressure. The concentrate was applied to a silica gel chromatography and 8.20 g (82%) of the title compound was obtained in the form of colorless crystals from a chloroform:methanol=100:1 to 30:1 eluate.

1. temperatureunder a nitrogen atmosphere while cooling with ice
2. temperaturewhile cooling with ice, it
3. temperaturewas heated
4. temperatureunder reflux
5. waitwas for 1.5 hours
6. temperaturecool
7. extractionit was extracted with ethyl acetate (10 ml×2)
8. washwashed with saturated saline solution (100 ml) The organic layer
9. dry with materialwas then dried over anhydrous sodium sulfate
10. filtrationafter filtering
11. concentrationthe filtrate was concentrated under a reduced pressure