Cesium carbonate (379 mg, 1.164 mmol) was added to a stirring solution of 5-bromo-2-(4-fluorophenyl)furo[2,3-b]pyridine (200 mg, 0.685 mmol), 4-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (269 mg, 1.027 mmol), Pd(Ph3P)4 (158 mg, 0.137 mmol) in 1,4-dioxane (5.7 mL) and Water (1.1 mL). It was heated to 90° C. overnight. The mixture was diluted with EtOAc and washed with 1M HCl, and sat NaCl. The organic phase was dried over Na2SO4, filtered and concentrated and diluted with MeOH/DCM and treated with TMS-diazomethane (685 μL, 1.37 mmol, 2M in ether). The mixture was allowed to stir for 1 hour. The reaction was concentrated and was purified on silica gel (Biotage, EtOAc/hexanes gradient, fraction collection at λ=254 nm) to give the expected product methyl 3-(2-(4-fluorophenyl)furo[2,3-b]pyridin-5-yl)-4-methylbenzoate (247 mg, 0.685 mmol, quant) by LCMS and NMR. 1H NMR (400 MHz, DMSO-d6) δ ppm 8.28 (1H, d, J=2.26 Hz), 8.16 (1H, d, J=2.01 Hz), 8.01-8.10 (2H, m), 7.93 (1H, dd, J=7.91, 1.88 Hz), 7.85 (1H, d, J=1.76 Hz), 7.49-7.57 (2H, m), 736-7.44 (2H, m), 3.86 (3H, s), 2.34 (3H, s). LC-MS retention time: 2.55 min; m/z (MH+): 362. 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.
