Reaction #3388

Reaction equation

HCl

tBuLi

5-bromopyrimidine

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

→

oil

Yield 18.0%

7a-(5-pyrimidinyl)-hexahydro-1H-pyrrolizine

Yield 18.0%

Solvents

pentane

Et2O THF

Et2O

Conditions

Workup

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 30 minutes
3. 3
   workup.STIRRINGstir for 1 hour
4. 4
   Otherthe phases separated
5. 5
   Extractionextracted with CH2Cl2 (2×)
6. 6
   Dryingdried (MgSO4)
7. 7
   Concentrationconcentrated
8. 8
   Otherthe residue was chromatographed (silica gel; CHCl3 /MeOH, 98:2)

Procedure

A solution of 1.7M tBuLi (1.6 mL, 2.6 mmol) in pentane was added to 5-bromopyrimidine (190 mg, 1.2 mmol) in Et2O:THF (1:1, 12 mL) at -100° C. After stirring for 10 minutes, 1,2,3,5,6,7-hexahydropyrrolizinium perchlorate (500 mg, 2.4 mmol) was added to the reaction slurry, and stirring was continued for 30 minutes. The reaction mixture was then allowed to warm to 0° C. and stir for 1 hour. A solution of 2N HCl was added, and the reaction mixture was poured over Et2O and the phases 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, 98:2) to afford a clear oil (40 mg, 18%). MS (CI/NH3) m/e: 190 (M+H)+. 1H NMR (CDCl3, 300 MHz) δ1.60-1.73 (m, 2H), 1.82-2.11 (m, 6H), 2.66-2.75 (m, 2H), 3.15-3.21 (m, 2H), 8.85 (s, 2H), 9.05 (s,1H).

Source