A mixture of tert-butyl 2-(4-bromo-3-methylphenyl)acetate (855 mg, 3.00 mmol), 4-(tributylstannyl)pyridazine (1162 mg, 3.15 mmol), Pd(PPh3)4 (173 mg, 0.15 mmol) and DMF (10 ml) was stirred under argon atmosphere at 118° C. overnight. After cooled to room temperature, the mixture was concentrated by evaporation of DMF, redissolved in ethyl acetate (50 ml) and washed with water (50 ml×2). After dried over Na2SO4 and concentrated by evaporation, the mixture was subjected to silica gel column chromatography with ethyl acetate/hexanes (1:1) as eluent to give tert-butyl 2-(3-methyl-4-(pyridazin-4-yl)phenyl)acetate 134-2 as an oil.
