Then, 4-(4-(2-isopropyl-phenylsulfanyl-3-trifluoromethyl-phenyl)-pyridine-1-oxide 75 was prepared as follows. A solution of compound 74 (2.51 g, 9.76 mmol) in dimethylacetamide (100 mL) was purged with nitrogen gas for 10 minutes. To it was added cesium carbonate (3.80 g, 11.7 mmol), followed by 2-isopropylthiophenol (4.90 mL, 29.3 mmol). The reaction was heated at 100° C. for 16 hours. The mixture was partitioned between ethyl acetate (200 mL) and water (200 mL). The organic layer was separated, washed with brine (5×200 mL), dried over MgSO4 and then filtered. After evaporating the solvent, the crude material was loaded to a silica gel column, eluting with 10% methanol in ethyl acetate to give a white solid 75 (3.19 g 84%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 3.51 (heptaplet, J=6.8 Hz, 1H), 6.90 (d, J=8.1 Hz, 1H), 7.22–7.28 (m, 1H), 7.44–7.51 (m, 6H), 7.84 (d, J=2.1 Hz, 1H), 8.24 (d, J=7.4 Hz, 2H); MS (DCI) m/z 390 (M+H)+.
