Hydrochloric Acid → Donepezil Hydrochloride

Participants

Reaction Steps

4.0 g of Donepezil was dissolved in 20 ml of methylene chloride at 18° C. The solution was cooled in an iced water bath. Hydrogen chloride gas was blown hereinto at 4° C. inner temperature, until the atmosphere turns acidic. Argon gas was blown hereinto. After stirring for 2 hours in an iced water bath, filtration of the separated crystals followed by drying afforded 4.09 g of the title compound. (water content: 0.81%)

Provenance & Evidence