反应详情

温度

-78 °C

3-Benzyloxy-5-bromopyridine (1.18 g, 4.47 mmol) was dissolved in Et2O and cooled to -78° C. A solution of 2.5M t-BuLi (5.8 mL, 9.83 mmol) in pentane was added, and the reaction was stirred for 10 minutes. 1,2,3,5,6,7-hexahydropyrrolizinium perchlorate (1.4 g, 6.70 mmol) was added, and the reaction mixture was allowed to stir for 3 hours at -78° C. then allowed to warm to -20° C. and stir for 2 hours. The cold bath was removed, 2N HCl was added, and the mixture was extracted with Et2O. The phases were separated, and the aqueous phase was basified with 15% NaOH and extracted with CH2Cl2 (2×). The CH2Cl2 fractions were combined, dried (MgSO4) and concentrated, and the residue was chromatographed (silica gel; CHCl3 /MeOH, 98:2) to afford a clear oil (286 mg, 22%): mp 45°-49° C. 1H NMR (CDCl3, 300 MHz) δ1.58-1.69 (m, 2H), 1.78-1.83 (m, 2H), 1.89-2.03 (m, 4H), 2.63-2.72 (m, 2H), 3.05-3.18 (m, 2H), 5.12 (s, 2H), 7.31-7.54 (m, 6H), 8.17 (d, J=3.0 Hz, 1H), 8.29 (d, J=1.7 Hz, 1H); MS (CI/NH3) m/z: 295 (M+H)+.

1. stirringto stir for 3 hours at -78° C.
2. temperatureto warm to -20° C.
3. stirringstir for 2 hours
4. customThe cold bath was removed
5. addition2N HCl was added
6. extractionthe mixture was extracted with Et2O
7. customThe phases were separated
8. extractionextracted with CH2Cl2 (2×)
9. dry with materialdried (MgSO4)
10. concentrationconcentrated
11. customthe residue was chromatographed (silica gel; CHCl3 /MeOH, 98:2)