反应详情

1,3-dibenzylpyrrolidine-3-carboxylic acid HCl salt (2.13 g, 7.2 mmol) was suspended in dry t-BuOH (40 mL) and Et3N (3.0 mL, 21.6 mmol) was added followed by diphenylphosphoryl azide (1.55 mL, 7.2 mmol). The mixture was heated at reflux for 2 d. The mixture was concentrated and the residue was taken up in EtOAc (150 mL) and washed with 10% aq Na2CO3 (50 mL) and brine (50 mL). The combined aqueous washes were back extracted with EtOAc (50 mL). The combined EtOAc layers were dried over Na2SO4. Removal of the solvent left a brown syrup (3.65 g) which was purified by chromatography on a 40-g silica gel cartridge eluted with a 0-20% MeOH in CH2Cl2 gradient to afford tert-butyl 1,3-dibenzylpyrrolidin-3-ylcarbamate (1.24 g, 47%).

1. temperatureThe mixture was heated
2. temperatureat reflux for 2 d
3. concentrationThe mixture was concentrated
4. washwashed with 10% aq Na2CO3 (50 mL) and brine (50 mL)
5. extractionThe combined aqueous washes were back extracted with EtOAc (50 mL)
6. dry with materialThe combined EtOAc layers were dried over Na2SO4
7. customRemoval of the solvent
8. waitleft a brown syrup (3.65 g) which
9. customwas purified by chromatography on a 40-g silica gel cartridge
10. washeluted with a 0-20% MeOH in CH2Cl2 gradient