Reaction #2838

Reaction equation

3-ethynyl-3-hydroxyquinuclidine

5-bromo-2-n-butoxypyridine

triethylamine

→

3-[2-(6-butoxy-3-pyridyl)ethynyl]quinuclidin-3-ol

Yield 25.2%

Solvents

dimethylformamide

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was cooled
2. 2
   Otherthe dimethylformamide and triethylamine were removed by evaporation
3. 3
   workup.ADDITIONThe residue was treated with 2M aqueous sodium hydroxide solution (20 ml)
4. 4
   Extractionthe resulting mixture extracted with dichloromethane (3×20 ml)
5. 5
   Dryingdried (MgSO4)
6. 6
   Otherevaporated
7. 7
   Otherto give a brown residue which
8. 8
   Otherwas crystallised from acetonitrile

Procedure

A stirred mixture of 3-ethynyl-3-hydroxyquinuclidine (600 mg), 5-bromo-2-n-butoxypyridine (920 mg), bis-(triphenylphosphine)-palladium (II) chloride (140 mg), copper (I) iodide (70 mg) and dry triethylamine (10 ml) in dry dimethylformamide (20 ml) was heated at 90° C. under an atmosphere of argon for 6 hours. The reaction mixture was cooled and the dimethylformamide and triethylamine were removed by evaporation. The residue was treated with 2M aqueous sodium hydroxide solution (20 ml) and the resulting mixture extracted with dichloromethane (3×20 ml). The organic extracts were combined, dried (MgSO4) and evaporated to give a brown residue which was crystallised from acetonitrile to yield 3-[2-(6-butoxy-3-pyridyl)ethynyl]quinuclidin-3-ol (300 mg) as a solid, m.p. 149°-151° C.; microanalysis, found: C, 71.3; H, 7.9; N, 8.9%; C18H24N2O2 0.1H 2O requires: C, 71.47; H, 8.08; N, 9.26%; NMR (DHSOd6): 0.9-1.0(3H, t), 1.2-1.35(1H, m), 1.35-1.5(2H, m), 1.5-1.65(1H, m), 1.65-1.75(2H, m), 1.75-2.0(3H, m), 2.6-2.75(4H, t), 2.8-2.85(1H, d), 3.02-3.17(1H, d), 4.2-4.3(2H, t), 5.55(1H, s), 6.75-6.83(1H, d), 7.65-7.72(1H, d) and 8.2(1H, s); m/Z 301 (M+H).

Source