A mixture of 4-(4-fluorophenyl)-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone (172 mg, 0.5 mmol), prepared according to the method of Example 10, Cu powder (32 mg), anhydrous K2CO3 (207 mg, 1.5 mmol) and 4-fluoroiodobenzene (0.12 mL, 1 mmol) was prepared in 20 mL of pyridine. The solution was stirred at reflux for 14 hours. The mixture was then cooled to room temperature and partitioned between water and ethyl acetate. The ethyl acetate layer was washed with 10% citric acid, water, brine and concentrated in vacuo. Separation by column chromatography (silica gel, CH2Cl2-diethyl ether 15:1) provided 190 mg of crude product. Crystallization from CH2Cl2-diethyl ether-hexanes furnished the title compound (yield: 175 mg, 79.9%). mp 168–169° C. 1H NMR (300 MHz, CDCl3) δ 3.07 (s, 3H), 6.98 (t, J=9 Hz, 2H), 7.20 (m, 4H), 7.40 (d, J=9 Hz, 2H), 7.69 (m, 2H), 7.92 (d, J=9 Hz, 2H), 7.98 (s, 1H). MS (DCI/NH3) m/z 439 (M+H)+, 456 (M+NH4)+. Anal. calc. for C23H16F2N2O3S.0.25 H2O: C, 62.36; H, 3.75; N, 6.32. Found: C, 62.23; H, 3.55; N, 6.26.
