Heat a mixture of 7-chloro-imidazo[1,2-a]pyridine (100 g, 152.5 mmol, 1 eq), 4-methylsulfonylphenyl boronic acid (157.3 g, 786.8 mmol, 1.2 eq), Pd(PPh3)4 (19 g, 16.3 mmol, 0.025 eq) and cesium carbonate (472.4 g, 1.44 mol, 2.2 eq) in a mixture of anhydrous DME (2000 mL) and EtOH (1000 mL) at 80° C. under N2 atmosphere for 24 hours. Cool the mixture to room temperature and filter through Celite® to remove Pd catalyst. Add water (5000 mL) and extract this solution with CH2Cl2 (3×2000 mL). Dry the organic phase over MgSO4 and evaporate. Add to the crude 2000 mL of CH2Cl2 and heat to reflux. Remove insoluble materials by filtration and evaporate the solvent to afford a yellow solid. Wash the solid with ethyl ether to give 150 g of the desired compound as a light yellow solid. (Yield: 85%). MS (ES), m/z 273 (M+1).
