Hydrochloric Acid → Donepezil Hydrochloride

Participants

Reaction Steps

After completing the hydrogenation, the catalyst was removed from the reaction solution followed by concentration. To the concentrated residue, 91 ml of ethanol was added to obtain a solution. Subsequently, the solution was crystallized under stirring. Precipitated crystals were filtered out, and then dried to obtain 10.6 g of donepezil. The obtained donepezil (9 g) was dissolved in 80 ml of ethanol. A mixed liquid of 2.7 g of concentrated hydrochloric acid and 10 ml of ethanol was added to the reaction solution under stirring, and the mixture was converted into its hydrochloride. After adding 135 ml of diisopropyl ether, the precipitated crystals were filtered out, and then dried to obtain 9.5 g of donepezil hydrochloride. The values of 1H-NMR of donepezil hydrochloride were consistent with those of Example 3.

Provenance & Evidence