In a 100 mL round bottomed flask was placed N-{4-[4-(4-chlorophenyl)-4,5,6,7-tetrahydro-1-benzothien-2-yl]pyridin-2-yl}acetamide (229.6 mg, 0.5996 mmol), 1,4-dioxane (15 mL) and acetonitrile (15 mL). To the mixture were added a solution of potassium persulfate (665.0 mg, 2.460 mmol) and copper (II) sulfate pentahydrate (68.9 mg, 0.276 mmol) in water (30 mL) and γ-collidine (320 uL, 2.4 mmol). The resulting blue-white suspension was stirred for 16 hr at 90° C. The mixture was allowed to cool to rt and then concentrated under reduced pressure to remove 1,4-dioxane and acetonitrile. The aqueous residue was extracted with EtOAc (50 mL×2). The combined organic phases were washed with 10% NaHSO3 aq (30 mL), saturated aqueous solution of NaHCO3 (30 mL), saturated aqueous solution of ammonium chloride (30 mL), and dried over anhydrous MgSO4. Insoluble materials were removed by filtration and the filtrate was concentrated under reduced pressure. The residue was purified by prepacked silica gel (24 g) column chromatography, eluting with 20% to 100% EtOA/hexane to yield the title compound (95 mg; 40%) as a colorless foam, which was recrystallized from EtOAc and ether to obtain a colorless crystalline solid. LCMS: (FA) ES+ 397, 399; 1H NMR (400 MHz, d6-DMSO) δ ppm 10.64 (br s, 1H), 8.30-8.34 (m, 2H), 7.40-7.45 (m, 3H), 7.29 (d, 2H), 7.21 (s, 1H), 4.39 (dd, 1H), 2.59-2.75 (m, 1H), 2.20-2.52 (m, 3H), 2.09 (s, 3H).
