Hydrochloric Acid → Donepezil Hydrochloride

Participants

Reaction Conditions

Reaction Steps

1.0 g of Donepezil was dissolved in 4 ml of methanol under heating at 40° C. The solution was cooled in an iced water bath. 0.31 g of Concentrated hydrochloric acid in 1 ml of methanol was added hereinto. After 5 minutes, 30 ml of tert-butyl methyl ether (hereinafter, abbreviated as TBME) was added at 3° C. inner temperature. It continued stirring for 30 minutes in an iced water bath. Filtration of the separated crystals followed by drying afforded 1.10 g of the title compound. (water content: 5.60%)

Provenance & Evidence