Darifenacin Dehydro Impurity → Darifenacin

Participants

Reaction Steps

10% Palladium-on-carbon (10 mg) was added to a solution of 3-(S)-(-)-(1-carbamoyl-1,1-diphenylmethyl)-1-[2-(benzofuran-5-yl)-ethyl]pyrrolidine (0.1 g-see Example 7) in acetic acid (2 ml) and the mixture was hydrogenated at 40° C. and atmospheric pressure for 6 hours. The catalyst was filtered off and washed with water (20 ml). The combined filtrate and washings were transferred to a separating funnel, dichloromethane (20 ml) was added, and the mixture was basified by the addition of 10% aqueous sodium hydroxide. The layers were separated and the aqueous layer was further extracted with dichloromethane (3×30 ml). The combined dichloromethane extracts were dried (MgSO4) and concentrated in vacuo to give a colourless solid which was purified by column chromatography on silica eluting with dichloromethane containing methanol (4%). The product-containing fractions were combined and concentrated in vacuo to give the title compound as a colourless glass, yield 0.048 g, which was characterised spectroscopically to be identical to the product of Example 1 (B).

Provenance & Evidence