反应详情

温度

-78 °C

To a solution of Compound 14A (0.68 g, 1.686 mmol) in dry THF (9.4 ml) at −78° C. under argon was added dropwise BuLi (0.742 ml, 1.855 mmol). After the completion of addition, the reaction mixture was stirred at −78° C. for 1 h. At the conclusion of this period, a solution of tert-butyl 4-oxopiperidine-1-carboxylate (0.37 g, 1.855 mmol) in THF (1.9 ml) was transferred to the reaction mixture via cannulation. The resulting mixture was stirred and gradually warmed to −20° C., where it stirred for an additional hour. At the conclusion of this period, the mixture was quenched with aq. NaHCO3 (saturated, 20 mL) and then extracted with EtOAc (3×15 mL). The combined organic layers were washed with H2O (3×10 mL) and brine (10 mL), dried (Na2SO4) and then filtered. The solvent was removed under reduced pressure, and the resulting residue was purified by column chromatography (silica gel, hexanes-EtOAc gradient 0 to 60% EtOAc) to give Compound 14B′ as a white solid (0.63 g, 68% yield). 1H NMR (500 MHz, chloroform-d) δ ppm 7.78 (d, J=1.7 Hz, 1H), 7.62 (d, J=8.5 Hz, 1H), 7.43 (dd, J=8.5, 1.9 Hz, 1H), 7.30-7.36 (m, 4H), 7.24-7.29 (m, 1H), 5.21 (tt, J=7.9, 3.9 Hz, 1H), 3.98 (br. s., 2H), 3.54 (s, 2H), 3.25 (br. s., 2H), 2.73 (br. s., 2H), 2.38 (t, J=8.7 Hz, 2H), 2.08-2.18 (m, 2H), 1.85-2.03 (m, 5H), 1.75 (d, J=12.1 Hz, 2H), 1.47-1.50 (m, 9H). LC/MS (m/z)=524 (M+H)+.

1. additionAfter the completion of addition
2. stirringThe resulting mixture was stirred
3. temperaturegradually warmed to −20° C.
4. stirringwhere it stirred for an additional hour
5. customAt the conclusion of this period, the mixture was quenched with aq. NaHCO3 (saturated, 20 mL)
6. extractionextracted with EtOAc (3×15 mL)
7. washThe combined organic layers were washed with H2O (3×10 mL) and brine (10 mL)
8. dry with materialdried (Na2SO4)
9. filtrationfiltered
10. customThe solvent was removed under reduced pressure
11. customthe resulting residue was purified by column chromatography (silica gel, hexanes-EtOAc gradient 0 to 60% EtOAc)