Galanthamine N-Oxide → (-)-Galantamine

Beteiligte Stoffe

Reaktionsschritte

A solution of 1.73 g (5.7 mmoles) of galanthamine N-oxide and 3.17 g (11,4 mmoles, 2 eq) of FeSO4 --7H2O in 100ml of methanol is agitated under argon for 1.5 hours at 10° C. After the evaporation of the solvent, the residue is taken up again in dichloromethane, treated with a saturated aqueous solution of sodium hydrogencarbonate and extracted three times with dichloromethane. The organic phases are collected and washed with a saturated aqueous solution of sodium chloride, dried on sodium sulfate and evaporated. The crude product of the reaction is purified by flash chromatography on silica gel using the mixture of dichloromethane/methanol (80:20) as eluant. The least polar fraction yields galanthamine and the most polar fraction yields for the most part norgalanthamine in the form of a white foam (yield=76%).

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