반응 #3386

반응 방정식

HCl

tBuLi

2,3-dichloro-5-iodopyridine

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

→

oil

수율 54.3%

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

수율 54.3%

용매

pentane

Et2O

반응 조건

후처리

1. 1
   기타precooled to -100° C
2. 2
   workup.STIRRINGto stir for 20 minutes at -100° C.
3. 3
   기타the cold bath was removed
4. 4
   온도After warming to ambient temperature
5. 5
   workup.ADDITIONthe reaction mixture was poured over EtOAc
6. 6
   기타the phases were separated
7. 7
   추출extracted with CH2Cl2 (2×)
8. 8
   건조dried (MgSO4)
9. 9
   농축concentrated
10. 10
    기타the residue was chromatographed (silica gel; CHCl3 /MeOH, 99.5:0.5)

실험 절차

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).

출처