Potassium Carbonate → Darifenacin Dehydro Impurity

Participants

Reaction Steps

A mixture containing 3-(S)-(-)-(1-carbamoyl-1,1-diphenylmethyl)pyrrolidine (1.79 g--see Preparation 10(B)), 5-(2-bromoethyl)benzo[2,3-b]furan (1.2 g--see Preparation 17), anhydrous potassium carbonate (3 g) and acetonitrile (30 ml) was heated under reflux for 30 minutes. The mixture was partitioned between ethyl acetate (30 ml) and 10% aqueous potassium carbonate (30 ml), the layers were separated, and the aqueous layer extracted with ethyl acetate (3×50 ml). The combined ethyl acetate extracts were dried (MgSO4) and concentrated in vacuo to give a brown gum which was purified by column chromatography on silica eluting with dichloromethane containing methanol (2%). The product-containing fractions were combined and concentrated in vacuo to give the title compound as a foam, yield 1.4 g.

Provenance & Evidence