反应详情

To a refluxing solution of 500 mg (1.486 mmol) rac-3-azido-3-phenyl-piperidine-1-carboxylic acid benzyl ester (example A.1, step 2) and 281 mg (7.43 mmol) NaBH4 in THF (5 ml) was added dropwise 2.0 ml methanol over 1.5 hour. The mixture was refluxed for another hour and then stirred at room temperature overnight. Another 114 mg (3 mmol) NaBH4 were added and the mixture was refluxed for 2 hours. The mixture was cooled in an ice bath and acidified with HCl 1N. The mixture was basified with 1N NaOH and extracted three times with ethyl acetate. The combined extracts were dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified on silica gel (Eluent: Heptane/ethyl acetate 0 to 100%) to provide 220 mg (48%) of the title compound as a colorless oil. MS (m/e): MS (m/e): 311.4 (M+H).

1. customover 1.5 hour
2. temperatureThe mixture was refluxed for another hour
3. temperaturethe mixture was refluxed for 2 hours
4. temperatureThe mixture was cooled in an ice bath
5. extractionextracted three times with ethyl acetate
6. dry with materialThe combined extracts were dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe crude product was purified on silica gel (Eluent: Heptane/ethyl acetate 0 to 100%)