反応 #3391

反応方程式

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

nBuLi

diisopropylamine

HCl

2,6-dichloropyridine

→

oil

収率 17.2%

7a-(2,6-dichloro-3-pyridinyl)-hexahydro-1H-pyrrolizine

収率 17.2%

溶媒

EtOAc

—

hexanes

THF

反応条件

後処理

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 1 hour at -78° C
3. 3
   workup.STIRRINGto stir for 2 hours at -78° C.
4. 4
   温度then warm to ambient temperature
5. 5
   その他The phases were separated
6. 6
   抽出extracted with CH2Cl2 (2×)
7. 7
   乾燥dried (MgSO4)
8. 8
   濃縮concentrated
9. 9
   その他the residue was chromatographed (silica gel; CHCl3 /MeOH, 98:2)

実験手順

A solution of 2.5M nBuLi (675 μL, 1.7 mmol) in hexanes was added to diisopropylamine (220 μL, 1.7 mmol) in THF (4.5 mL) at ambient temperature. After 10 minutes of stirring, the reaction mixture was cooled to -78° C., 2,6-dichloropyridine (237 μL, 1.60 mmol) was added neat, and stirring was continued for 1 hour at -78° C. 1,2,3,5,6,7-hexahydropyrrolizinium perchlorate (500 mg, 2.40 mmol) was added, and the reaction mixture was allowed to stir for 2 hours at -78° C. then warm to ambient temperature. A solution of 2N HCl was added, and the mixture was then poured over EtOAc. 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 (70.6 mg, 17%). MS (CI/NH3) m/e: 257/259 (M+H)+. 1H NMR (CDCl3, 300 MHz) δ1.47-1.61 (m, 2H), 1.77-1.90 (m, 2H), 2.10-2.25 (m, 4H), 2.67-2.75 (m, 2H), 3.03-3.11 (m, 2H), 7.19 (d, J=8.5 Hz, 1H), 8.37 (d, J=8.5 Hz, 1H).

出典