[(8-Bromo-6-chloro-4-hydroxy-2-oxo-2H-thiochromene-3-carbonyl)-amino]-acetic acid ethyl ester (22(d)) (500 mg, 1.2 mmol) was dissolved in DME-aqueous sodium carbonate (2M) (7 mL: 1.5 mL). To the solution was added 3,5-bis-trifluoromethyl-phenyl boronic acid (372 mg, 1.44 mmol) and tetrakis(triphenylphosphino) palladium(0) (275 mg, 0.24 mmol). The mixture was heated to reflux for six hours, cooled and concentrated. The residue was triturated with hot methanol (20 mL) and filtered to provide the title compound (470 mg.) MS ESI(−) m/e: 524.114, 526.018 (M−1).
