A mixture of 7-bromo-2-methyl-3-((E)-1-propyl-but-1-enyl)-2H-indazole (1.47 g, 4.79 mmol), 2,4-dichlorophenyl boronic acid (1.32 g, 6.94 mmol), 18 mL of ethylene glycol dimethyl ether, tetrakis(triphenylphosphine)palladium(0) (0.166 g, 0.143 mmol), and 20 mL of a 2 M aqueous Na2CO3 solution was stirred at 85° C. overnight, then allowed to cool. Ethyl acetate (50 mL) was added, and the mixture was washed with two 40 mL portions of a saturated aqueous NaCl solution. The combined aqueous layers were extracted with 20 mL of ethyl acetate. The combined organic layers were dried over Na2SO4, filtered, and concentrated to a brown oil. Column chromatography (0→5% EtOAc/hexanes) afforded 7-(2,4-dichloro-phenyl)-2-methyl-3-((E)-1-propyl-but-1-enyl)-2H-indazole (15a; 1.57 g; 88%) as a white solid.
