Hydrogen Bromide → Darifenacin nitrile hydrobromide

Participants

Reaction Conditions

Reaction Steps

To a slurry of (S)-2-{1-[2-(2,3-dihydrobenzofuran-5-yl)ethyl]-3-pyrrolidinyl}-2,2-diphenylacetonitrile (V) (30.0 g, 0.073 moles) in methanol (150 mL) is added 48% aqueous hydrobromic acid (13.6 g, 0.081 moles) maintaining the temperature below 40° C. The mixture is heated at reflux for 1 hour. The batch is cooled to 0° C., and the product is collected by filtration, washed with methanol (60 mL) and dried at 50° C. under vacuum to give (S)-2-{1-[2-(2,3-dihydrobenzofuran-5-yl)ethyl]-3-pyrrolidinyl}-2,2-diphenylacetonitrile hydrobromide (VI) (33.5 g, 93%).

Provenance & Evidence