Lithium diisopropylamide (Aldrich Chemical Company, 2M in tetrahydrofuran/ethylbenzene, 4 mL, 7.94 mmol) was added to tetrahydrofuran (4 mL) at −78° C. A solution of 1-(4-bromo-1-naphthalenyl)ethanone (1.8 g, 7.22 mmol) in tetrahydrofuran (4 mL) was added dropwise to the mixture. When the addition was complete the mixture was stirred for 30 min at −78° C. Then a solution of 1-(3,5-dichlorophenyl)-2,2,2-trifluoroethanone (1.75 g, 7.20 mmol) in tetrahydrofuran (4 mL) was added dropwise to the mixture at such a rate that the temperature of the reaction mixture did not exceed −55° C. The mixture was allowed to warm to ambient temperature over 120 min. The mixture was then poured into 1N hydrochloric acid (100 mL) and extracted with ethyl acetate (2×100 mL). The combined extracts were dried and evaporated. Chromatography on silica gel (eluted with 1:9 ethyl acetate/hexanes) and crystallization from hexanes gave the title product as a white solid (1.1 g, 40% yield) melting at 74.5-75° C. (after recrystallization from hexanes).
