Reaction #3421

Reaction equation

n-BuLi

di-isopropylamine

7a-(6-Fluoro-3-pyridinyl)-hexahydro-1H-pyrrolizine

1,2-dibromo-1,1,2,2-tetrafluoroethane

→

title compound

Yield 37.4%

7a-(5-bromo-6-fluoro-3-pyridinyl)-hexahydro-1H-pyrrolizine

Yield 37.4%

Solvents

THF

Conditions

Workup

1. 1
   Temperaturecooled to -78° C
2. 2
   TemperatureThe mixture was slowly warmed to room temperature
3. 3
   workup.STIRRINGstirred overnight
4. 4
   OtherThe reaction was quenched with 2N HCl
5. 5
   Washthe mixture was washed with Et2O
6. 6
   Extractionextracted with methylene chloride
7. 7
   Otherdried
8. 8
   Concentration(MgSO4) and concentrated
9. 9
   OtherThe residue was chromatographed (silica gel; CHCl3 /MeOH, 99:1)

Procedure

n-BuLi (2.5M in hexanes, 0.252 mL, 0.63 mmol) was added to di-isopropylamine (0.082 mL, 0.63 mmol) in THF and stirred at room temperature for 10 minutes, then cooled to -78° C. 7a-(6-Fluoro-3-pyridinyl)-hexahydro-1H-pyrrolizine (123 mg, 0.60 mmol, from Example 12d) and 1,2-dibromo-1,1,2,2-tetrafluoroethane (0.215 mL, 1.80 mmol) were added. The mixture was slowly warmed to room temperature and stirred overnight. The reaction was quenched with 2N HCl, and the mixture was washed with Et2O. The aqueous layer was basified with 15% NaOH and extracted with methylene chloride. The organic extracts were combined, dried, (MgSO4) and concentrated. The residue was chromatographed (silica gel; CHCl3 /MeOH, 99:1) to afford the title compound as an oil (64 mg, 37%). 1H NMR (CDCl3, 300 MHz) δ1.59-1.71 (m, 2H), 1.79-2.06 (m, 6H), 2.64-2.72 (m, 2H), 3.12-3.19 (m, 2H), 8.14 (dd, J=8.8, 2.2 Hz, 1H), 8.19 (dd, J=2.2, 1.2 Hz, 1H); MS (CI/NH3) m/z: 285/287 (M+H)+.

Source