Hydrochloric Acid → 2-((3-Pyridinyl)methyl)-1-azabicyclo[2.2.2]octan-3-one hydrochloride

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Reaction Steps

2-((3-Pyridinyl)methylene)-1-azabicyclo[2.2.2]octan-3-one (20 g, 93 mmol) was suspended in methanol (200 mL) and treated with 46 mL of 6N HCl. 10% Palladium on carbon (1.6 g) was added and the mixture was shaken under 25 psi hydrogen for 16 h. The mixture was filtered through Celite and solvent removed from the filtrate by rotary evaporation, to give crude 2-((3-pyridinyl)methyl)-1-azabicyclo[2.2.2]octan-3-one hydrochloride as a white gum (20 g). This was treated with 2N NaOH (50 mL) and chloroform (50 mL) and stirred for an hour. The chloroform layer was separated and the aqueous phase was treated with 2N NaOH, enough to raise the pH to 10 (about 5 mL), and saturated aqueous NaCl (25 mL). This was extracted with chloroform (3×10 mL), and the combined extracts were dried (MgSO4) and concentrated by rotary evaporation. The residue (18 g) was dissolved in warm ether (320 mL) and cooled to 4° C. The white solid was filtered off, washed with a small portion of cold ether and air dried. Concentration of the filtrate to ˜10% of its former volume and cooling at 4° C. produced a second crop. A combined yield 16 g (79%) was obtained.

Provenance & Evidence