Water → 3-(2-Pyrazinyl)-1-azabicyclo[2.2.2]oct-2-ene

HRID 256870Notes

Reaction equation

HRID 256870 reaction equation
S(Cl)(Cl)=O.[N:5]1[CH:10]=[CH:9][N:8]=[CH:7][C:6]=1[C:11]1(O)[CH:16]2[CH2:17][CH2:18][N:13]([CH2:14][CH2:15]2)[CH2:12]1.O.C(=O)([O-])[O-].[K+].[K+]>ClCCl>[N:5]1[CH:10]=[CH:9][N:8]=[CH:7][C:6]=1[C:11]1[CH:16]2[CH2:17][CH2:18][N:13]([CH2:14][CH2:15]2)[CH:12]=1

Participants

6

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 24386Thionyl ChlorideHCID 157501353-(2-Pyrazinyl)-1-azabicyclo[2.2.2]octan-3-ol

Product 1

HCID 157501423-(2-Pyrazinyl)-1-azabicyclo[2.2.2]oct-2-eneYield 73.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Thionyl chloride (0.24 g. 1.55 mmol) was added dropwise to a rapidly stirred solution of 3-(2-pyrazinyl)-1-azabicyclo[2.2.2]octan-3-ol (0.21 g, 1.02 mmol) in dichloromethane (10 ml) at -5° C. The reaction mixture was warmed to room temperature and then refluxed for 3 h. Water (5 ml) was added to the solution, basified to pH >10 with potassium carbonate and extracted with dichloromethane (3×50 ml). The combined extracts were dried (Na2SO4), the solvent removed under vacuum and the residue chromatographed through alumina (Grade II-III) using dichloromethane/methanol (98:2) as eluant to give 3-(2-pyrazinyl)-1-azabicyclo[2.2.2]oct-2-ene as a pale yellow solid (0.14 g), δ (360 MHz, CDCl3) 1.54-1.61 (2H, m, CH2); 1.77-1.95 (2H, m, CH2); 2.63-2.71 (2H, m, CH2 --N); 3.02-3.09 (2H, m, CH2 --N); 3.53-3.56 (1H, m, CH-bridgehead); 7.30 (1H, d, J=1.5 Hz vinyl-H); 8.41 (1H, d, J=2 Hz, pyrazine-H); 8.52 (1H, dd, J=1 and 2 Hz, pyrazine-H) 8.78 (1H, d, J=1 Hz, pyrazine-H).

Workup

  1. temperaturerefluxed for 3 h
  2. extractionextracted with dichloromethane (3×50 ml)
  3. dry with materialThe combined extracts were dried (Na2SO4)
  4. customthe solvent removed under vacuum
  5. customthe residue chromatographed through alumina (Grade II-III)

Sources & evidence

ORD record
ord-8028567ebaa140d7a3a6301c9136170f
Source dataset
uspto-grants-1993_11
Patent number
US05260293

Reaction notes

Loading…