反应 #3386

反应方程式

HCl

tBuLi

2,3-dichloro-5-iodopyridine

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

→

oil

收率 54.3%

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

收率 54.3%

溶剂

pentane

Et2O

反应条件

后处理

1. 1
   其他precooled to -100° C
2. 2
   workup.STIRRINGto stir for 20 minutes at -100° C.
3. 3
   其他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
   其他the phases were separated
7. 7
   萃取extracted with CH2Cl2 (2×)
8. 8
   干燥dried (MgSO4)
9. 9
   浓缩concentrated
10. 10
    其他the residue was chromatographed (silica gel; CHCl3 /MeOH, 99.5:0.5)

实验过程

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).

来源