To a mixture of 2-(4-bromo-2-ethylphenyl)cyclopentane-1,3-dione (0.20 g, 0.0007 mol), 4-chlorophenol (0.180 g, 0.0014 mol), cesium carbonate (0.460 g, 0.0014 mol), copper triflate (10 mg, 0.00003 mol) and activated 4 Å molecular sieves (0.30 g) is added anhydrous toluene (7 ml). The mixture is then heated at 16° C. for 1 hour under microwave irradiation, followed by dilution with ethyl acetate (50 ml) and 2M hydrochloric acid (50 ml). The organic phase is separated, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The crude product is purified by preparative reverse phase HPLC to afford 2-[4-(4-chlorophenoxy)-2-ethylphenyl]-3-hydroxycyclopent-2-enone as a cream solid.
