3-Carboxyphenylboronic acid (700 mg, 4.22 mmol), 5-bromo-2-(4-fluorophenyl)furo[2,3-b]pyridine (750 mg, 2.57 mmol), Pd(Ph3P)4 (30 mg, 0.026 mmol), and Cs2CO3 (1.25 g, 3.84 mmol) were combined in dioxane (20 mL) and water (4 mL). The mixture was evacuated/backfilled with nitrogen (3×). The reaction was heated to 95° C. under N2 (g) overnight. The mixture was partitioned between EtOAc and 1N HCl. The organic phase was washed with water and brine, dried over MgSO4, filtered, and concentrated to give a brown solid which was triturated with Et2O to give the expected product 3-(2-(4-fluorophenyl)furo[2,3-b]pyridin-5-yl)benzoic acid (255 mg, 30% yield) consistent by LCMS. LC-MS retention time: 1.83 min; m/z (MH+): 334. LC data was recorded on a Shimadzu LC-10AS liquid chromatograph equipped with a Phenomenex-Luna 10u 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 5 ml/min, a gradient of 100% solvent A/0% solvent B to 0% solvent A/100% solvent B, a gradient time of 2 min, a hold time of 1 min, and an analysis time of 3 min where solvent A was 10% MeOH/90% H2O/0.1% trifluoroacetic acid and solvent B was 10% H2O/90% MeOH/0.1% trifluoroacetic acid. MS data was determined using a Micromass Platform for LC in electrospray mode.
