To a degassed solution containing 2-(4-fluorophenyl)-3-(methylcarbamoyl)benzo[b]thiophen-5-yl trifluoromethanesulfonate (0.32 g, 0.74 mmol), 3-boronobenzoic acid (0.18 g, 1.1 mmol), cesium carbonate (0.36 g, 1.1 mmol), dioxane (6.2 mL) and water (1.2 mL) was added tetrakis(tiphenylphosphine)palladium(0) (0.02 g, 0.016 mmol). The solution was maintained at 95° C. for 90 min. The solution was cooled to room temperature, concentrated and suspended in ethyl acetate (20 mL) with stirring for 1 h. The mixture was filtered, washed with water (3×20 mL) and air dried to afford 3-(2-(4-fluorophenyl)-3-(methylcarbamoyl)benzo[b]thiophen-5-yl)benzoic acid as a grey solid which was used without further purification. LCMS: retention time: 2.132 min. LC data was recorded on a Shimadzu LC-10AS liquid chromatograph equipped with a Phenomenex-Luna, 10 micron, C18, 3.0×50 mm column using a SPD-10AV UV-Vis detector at a detector wave length of 220 nM. The elution conditions employed a flow rate of 4 mL/min, a gradient of 100% solvent A/0% solvent B to 0% solvent A/100% solvent B, a gradient time of 4 min, a hold time of 1 min, and an analysis time of 5 min where solvent A was 10% CH3CN/90% H2O/10 mM TFA and solvent B was 10% H2O/90% CH3CN/10 mM TFA. MS data was determined using a Micromass Platform for LC in electrospray mode. m/z 406 (MH+).
