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, 645 ml of ethanol was added to obtain a solution. Subsequently, the solution was crystallized under stirring. Crystallized donepezil was filtered out, and then dried to obtain 76.3 g of donepezil. The obtained donepezil (75.8 g) was dissolved in 606 ml of ethanol. To the reaction solution, 22.8 g of concentrated hydrochloric acid was added under stirring, and the mixture was converted into its hydrochloride. The precipitated crystals were filtered out, and then dried to obtain 80.2 g of donepezil hydrochloride. The values of 1H-NMR were consistent with those of Example 3.

Provenance & Evidence