反应详情

To (S)-Benzyl 3-carbamoyl-3-methylpyrrolidine-1-carboxylate (35.61 g, 135.8 mmol) in 1:1 MeCN/H2O (100 mL) was added [bis(trifluoroacetoxy)iodo]benzene (58.38 g, 135.8 mmol). The reaction mixture was stirred at ambient temperature for 2 hours and then at 86° C. (bath) for 2 hours. After cooling to ambient temperature, concentrated HCl (14.85 g, 407.3 mmol) and ether (200 mL) were added. The aqueous layer was separated and basified by K2CO3 (46.91 g, 339.4 mmol). To the resulting solution was added THF (150 mL) and Boc2O (37.04 g, 169.7 mmol). The reaction mixture was stirred at ambient temperature for 1 hour. Ethyl acetate (100 mL) was added. The organic layer was separated, washed with brine, dried (sodium sulfate), filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (3:1 hexane/ethyl acetate) on silica gel to give (S)-benzyl 3-(tert-butoxycarbonylamino)-3-methylpyrrolidine-1-carboxylate (42.30 g, 126.5 mmol, 93.2% yield) as an oil.

1. waitat 86° C. (bath) for 2 hours
2. temperatureAfter cooling to ambient temperature
3. customThe aqueous layer was separated
4. stirringThe reaction mixture was stirred at ambient temperature for 1 hour
5. customThe organic layer was separated
6. washwashed with brine
7. dry with materialdried (sodium sulfate)
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified by flash chromatography (3:1 hexane/ethyl acetate) on silica gel