In argon atmosphere, a mixture of 16.65 g (69.9 mmol) of 9,9-dimethyl-9H-fluorene-2-ylboronic acid, 20.0 g (69.9 mmol) of 2,6-dibromonaphthalene, 4.04 g (3.50 mmol) of tetrakis(triphenylphosphine)palladium (0), 200 ml of toluene, 200 ml of dimethoxyethane, and 106 g of a 2 M sodium carbonate aqueous solution was stirred at 85° C. for 8 h and left standing overnight. After adding water, the mixture was stirred at room temperature for one hour. After filtration and extraction with toluene, the organic phase was washed with water and then with a saturated saline solution. After drying over sodium sulfate, the toluene was distilled off under reduced pressure. The obtained brown oily substance was purified by silica gel chromatography to obtain 11.84 g (yield: 42.4%) of 2-(6-bromonaphthalene-2-yl)-9,9-dimethyl-9H-fluorene.
