Sodium hydride (80% dispersion in mineral oil, 250 mg) was added to a solution of 1,3-dihydro-2H-indol-2-one (1.12 g) in dry DMF (5 ml at 0° C. The mixture was allowed to warm to room temperature and after 50 minutes a solution of 1-(2-chloroethyl)-4-(phenylmethyl)piperazine (2.02 g) in dry DMF (6 ml) was added. The reaction mixture was then heated at 80° C. for 2 hours and then evaporated to dryness under reduced pressure. The residue was purified by flash chromatography on silica gel to afford the title compound (1.1 g, 40%) as an oil.
