反応 #3386

反応方程式

HCl

tBuLi

2,3-dichloro-5-iodopyridine

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

→

oil

収率 54.3%

7a-(5,6-dichloro-3-pyridinyl)-hexahydro-1H-pyrrolizine

収率 54.3%

溶媒

pentane

Et2O

反応条件

後処理

1. 1
   その他precooled to -100° C
2. 2
   workup.STIRRINGto stir for 20 minutes at -100° C.
3. 3
   その他the cold bath was removed
4. 4
   温度After warming to ambient temperature
5. 5
   workup.ADDITIONthe reaction mixture was poured over EtOAc
6. 6
   その他the phases were separated
7. 7
   抽出extracted with CH2Cl2 (2×)
8. 8
   乾燥dried (MgSO4)
9. 9
   濃縮concentrated
10. 10
    その他the residue was chromatographed (silica gel; CHCl3 /MeOH, 99.5:0.5)

実験手順

A solution of 1.7M tBuLi (4.7 mL, 8.0 mmol) in pentane was added to 2,3-dichloro-5-iodopyridine (from step 8a, 1.0 g, 3.65 mmol) in Et2O (15 mL) precooled to -100° C. After stirring for 2 minutes, 1,2,3,5,6,7-hexahydropyrrolizinium perchlorate (1.5 g, 7.3 mmol) was added, and the reaction mixture was allowed to stir for 20 minutes at -100° C. then gradually warm to -20° C. A solution of 2N HCl was added, and the cold bath was removed. After warming to ambient temperature, the reaction mixture was poured over EtOAc and the phases were separated. The aqueous phase was basified with 15% NaOH solution and extracted with CH2Cl2 (2×). The CH2Cl2 phases were combined, dried (MgSO4), concentrated and the residue was chromatographed (silica gel; CHCl3 /MeOH, 99.5:0.5) to afford a light yellow oil (510 mg, 54%). MS (CI/NH3) m/e: 257 (M+H)+. 1H NMR (CDCl3, 300 MHz) δ1.59-1.71 (m, 2H), 1.80-2.08 (m, 6H), 2.64-2.72 (m, 2H), 3.11-3.20 (m, 2H), 7.99 (d, J=2.2 Hz, 1H), 8.36 (d, J=2.2 Hz, 1H).

出典