A mixture of 3-bromo-1-[3-(trifluoromethyl)phenyl]pyridazin-4(1H)-one (137 mg, 0.428 mmol), (2-phenylthiophen-3-yl)boronic acid (87.4 mg, 0.428 mmol), Na2CO3 (136 mg, 1.28 mmol) and Pd(PPh3)4 (24.7 mg, 0.021 mmol) in DME (1.6 mL) and water (0.49 mL) was heated to 80° C. for 18 h under Ar atmosphere. The mixture was diluted with water, extracted with AcOEt, washed with NaHCO3 aqueous solution, dried over Na2SO4, filtered, concentrated in vacuo, purified by column chromatography on basic silica gel (hexane/AcOEt=80/20 to 0/100) and recrystallized with AcOEt/heptane to yield the title compound (38.6 mg, 23% yield) as a white solid: mp 167-168° C. 1H NMR (DMSO-d6, 300 MHz): δ ppm 6.62 (1H, d, J=8.0 Hz), 7.30-7.41 (5H, m), 7.47 (1H, brs), 7.51 (1H, d, J=5.2 Hz), 7.55-7.72 (4H, m), 8.91 (1H, d, J=8.0 Hz). Anal. Calcd for C21H13F3N2OS: C, 63.31; H, 3.29; N, 7.03. Found: C, 63.08; H, 3.37; N, 7.01.
