To a solution of 1-bromo-4,5-dimethoxy-2-nitrobenzene (1.06 g, 4.04 mmol) produced in Example (87a) in 1,2-dimethoxyethane (30 mL) were added 4,4,5,5-tetramethyl-2-(3,3,5,5-tetramethylcyclohex-1-enyl)[1,3,2]dioxaborolane (1.28 g, 4.85 mmol) produced in Example (4b), tripotassium phosphate (1.29 g, 6.06 mmol) and water (1.5 mL). Tetrakis(triphenylphosphine)palladium (230 mg, 0.20 mmol) was then added to the mixture while stirring at room temperature under a nitrogen atmosphere. The mixture was then stirred for 13 hours at an external temperature of 70° C., and stirring was continued for 3 hours at an external temperature of 100° C. Tetrakis(triphenylphosphine)palladium(0) (230 mg, 0.20 mmol) and water (2 mL) were added to the reaction mixture, and it was further stirred for 9 hours at an external temperature of 100° C. and then for 11 hours at an external temperature of 70° C. After cooling the reaction mixture, ethyl acetate was added and the mixture was filtered through Celite. The filtrate was concentrated and extracted with ethyl acetate, and the obtained organic layer was washed with brine. The organic layer was then dried over anhydrous magnesium sulfate, the desiccant was filtered off, and the filtrate was concentrated under reduced pressure. The resultant residue was purified by silica gel column chromatography (ethyl acetate/heptane) to give 1.1 g of the title compound as a brown oil.
