反应详情

To a 50 ml round bottom flask was added (3S)-2-{[(1,1-dimethylethyl)oxy]carbonyl}-3-pyrazolidinecarboxylic acid (431 mg, 1.99 mmol) in methanol (15 mL), followed by iodobenzene diacetate (770 mg, 2.39 mmol). The mixture was stirred at room temperature for 10 min, and LCMS indicated the reaction was complete. The organic solvent was removed under vacuum, and the residue was taken up in 1 M aq. NaHCO3 (30 mL). The aqueous mixture was washed with DCM (3×20 mL), acidified with 6 N HCl to ˜pH 2.0, and then extracted with DCM (3×30 mL). The combined organic extracts were dried (Na2SO4), filtered, and concentrated under vacuum to afford (5S)-1-{[(1,1-dimethylethyl)oxy]carbonyl}-4,5-dihydro-1H-pyrazole-5-carboxylic acid (273 mg, 1.27 mmol, 64% yield) as a clear oil.

1. customThe organic solvent was removed under vacuum
2. washThe aqueous mixture was washed with DCM (3×20 mL)
3. extractionextracted with DCM (3×30 mL)
4. dry with materialThe combined organic extracts were dried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated under vacuum