Reaktion #3406

Reaktionsgleichung

3-Benzyloxy-5-bromopyridine

t-BuLi

1,2,3,5,6,7-hexahydropyrrolizinium perchlorate

→

oil

Ausbeute 22.0%

7a-(3-benzyloxy-5-pyridinyl)-hexahydro-1H-pyrrolizine

Ausbeute 22.0%

Lösungsmittel

Et2O

pentane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGto stir for 3 hours at -78° C.
2. 2
   Temperaturto warm to -20° C.
3. 3
   workup.STIRRINGstir for 2 hours
4. 4
   SonstigeThe cold bath was removed
5. 5
   workup.ADDITION2N HCl was added
6. 6
   Extraktionthe mixture was extracted with Et2O
7. 7
   SonstigeThe phases were separated
8. 8
   Extraktionextracted with CH2Cl2 (2×)
9. 9
   Trocknendried (MgSO4)
10. 10
    Einengenconcentrated
11. 11
    Sonstigethe residue was chromatographed (silica gel; CHCl3 /MeOH, 98:2)

Vorschrift

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)+.

Quelle