NaOH (3.3 mL, 3.3 mmol, 1M aq) was added to a stirring solution of methyl 3-(3-bromo-2-(4-fluorophenyl)furo[2,3-b]pyridin-5-yl)-4-methylbenzoate (294 mg, 0.668 mmol) in MeOH (7 mL) and THF (7 mL) at 60° C. It was allowed to stir for 1 hr. The mixture was diluted with EtOAc and washed with 1M HCl, and sat NaCl. The organic phase was dried over Na2SO4, filtered and concentrated to give the expected product 3-(3-bromo-2-(4-fluorophenyl)furo[2,3-b]pyridin-5-yl)-4-methylbenzoic acid (275 mg, 0.645 mmol, 97% yield) consistent by LCMS and NMR. 1H NMR (400 MHz, DMSO-d6) δ ppm 12.90 (1H, br. s.), 8.40 (1H, d, J=2.26 Hz), 8.18-8.25 (2H, m), 8.05 (1H, d, J=2.26 Hz), 7.92 (1H, dd, J=7.78, 1.76 Hz), 7.85 (1H, d, J=1.76 Hz), 7.43-7.54 (3H, m), 2.35 (3H, s). LC-MS retention time: 2.42 min; m/z (MH+): 426, 428. LC data was recorded on a Shimadzu LC-10AS liquid chromatograph equipped with a Waters SunFire 5u C18 4.6×50 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 3 min, a hold time of 1 min, and an analysis time of 4 min where solvent A was 10% acetonitrile/90% H2O/0.1% trifluoroacetic acid and solvent B was 10% H2O/90% acetonitrile/0.1% trifluoroacetic acid. MS data was determined using a Micromass Platform for LC in electrospray mode.
