Benzaldehyde → Donepezil

Participants

Reaction Steps

0.22 g of 2,3-dihydro-5,6-dimethoxy-2-((piperidin-4-yl)methyl)inden-1-one p-toluenesulfonic acid salt, and 0.10 g of sodium acetate were added to 60 mL of anhydrous methanol. 100 milligrams of 10% Pd/C were also added. The reaction mixture was stirred at room temperature with H2 being supplied at 1 atmosphere for 10 hours. 55 milligrams of benzaldehyde were added in equal portions at 0 hrs, 2 hrs, 4 hrs, 6 hrs and 8 hrs. Solids were filtered off. The filtrate was concentrated. 30 mL of 5% aqueous Na2CO3 solution were added, and the resulting mixture was extracted with 3×30 mL of ethyl acetate. The extracts were combined, washed with 15 mL of aqueous Na2CO3 solution and 15 mL of aqueous NaCl solution, and dried over anhydrous MgSO4. After solids were filtered off, solvent was removed in vacuo to afford 0.67 g of product as oil. Purification on silica gel column chromatography afforded 0.11 g of title compound in 62% yield.

Provenance & Evidence