Potassium Carbonate → 2,2-diphenyl-5-[N-{2-(2,3-dihydrobenzofur-5-yl)ethyl}-N-methylamino]pentanamide

A mixture containing 2,2-diphenyl-5-methylaminopentanamide (0.3--see Preparation 3), 5-(2-bromoethyl)-2,3-dihydrobenzofuran (0.242 g--see Preparation 20), anhydrous potassium carbonate (0.4 g) and acetonitrile (10 ml) was heated under reflux for 5 hours. The mixture was concentrated in vacuo and the residue partitioned between dichloromethane (30 ml) and 10% aqueous potassium carbonate (30 ml). The layers were separated and the aqueous layer extracted with dichloromethane (3×20 ml). The combined dichloromethane extracts were dried (MgSO4) and concentrated in vacuo to give a gum which was purified by column chromatography on silica eluting with dichloromethane containing methanol (5% up to 10%). The product-containing fractions were combined and concentrated in vacuo to give the title compound as a gum, yield 0.26 g.