At 0° C., 280 mg (1.85 mmol) of 4-fluoro-2,3-dihydro-1H-isoindol-1-one were added to a suspension of 96.3 mg (2.41 mmol, 60% pure) of sodium hydride in 1 ml of DMF. The mixture was stirred for 30 min, and 654.5 mg (1.85 mmol) of tert-butyl(+/−)-[4-(bromomethyl)phenyl](cyclopentyl)acetate were then added at 0° C. Stirring was continued for a further 2 h, and water and ethyl acetate were then added to the reaction mixture. The organic phase was washed with saturated sodium chloride solution and dried over magnesium sulfate. The crude product was purified by chromatography on silica gel (mobile phase cyclohexane/ethyl acetate 6:1 to 5:1). This gave 394 mg (50.2% of theory) of the target compound.
