A suspension of methyl 5-bromo-6-fluoro-2-methyl-2H-indazole-4-carboxylate (503 mg, 1.75 mmol), palladium acetate (39.3 mg, 0.175 mmol), triphenylphosphine (91.8 mg, 0.350 mmol), potassium carbonate (266 mg, 1.93 mmol) and methyl acrylate (314 μL, 3.50 mmol) in N,N-dimethylformamide (8.8 mL) was stirred with heating at 100° C. for 1 hr. The reaction solution was diluted with ethyl acetate, washed with water and saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate/hexane=10/90→60/40) to give the title compound (452 mg, yield 88%).
