A mixture of methyl 4-borono-3-chlorobenzoate (Combi-Blocks BB-3530, 1.5 g, 7.0 mmol), 2-bromobenzotrifluoride (1.9 g, 8.4 mmol), cesium fluoride (3.2 g; 21.0 mmol) and bis(triphenylphosphine)palladium(II) chloride (98 mg, 0.14 mmol) was prepared in dioxane (15 mL) and water (7.5 mL) under nitrogen atmosphere, and then heated at 90° C. for 30 minutes. The reaction mixture was diluted with MTBE (30 mL) and washed with water and brine. The aqueous layers were extracted with MTBE (30 mL). The combined organic layers were dried (MgSO4) and concentrated under vacuum. After two purifications by flash chromatography (silica, heptane/DCM, then heptane/EtOAc), the title compound was obtained as a yellow oil. HPLC (Method A) Rt 5.3 min (Purity: 99.7%).
