1-Bromo-2-iodobenzene → (2-Bromophenyl)diphenylphosphine

According to the method described in a literature (S. E. Tunney and J. K. Stille, J. Org. Chem., 1987, 52, 748), (2-bromophenyl)diphenylphosphine was obtained by reacting 2-bromoiodobenzene and (trimethylsilyl)diphenylphosphine in toluene in the presence of dichlorobis(acetonitrile)palladium. Into a four-necked flask was weighed 10.00 g (29.3 mmol) of (2-bromophenyl)diphenylphosphine obtained in the above. The atmosphere of the reaction vessel fitted with a thermometer, a condenser tube, and a dropping funnel with a pressure-equalizing tube was completely replaced with nitrogen, and 100 mL of anhydrous tetrahydrofuran (hereinafter referred to as THF) was added thereto. Thereto was added dropwise 18.3 mL of n-butyllithium-hexane (1.6 M) solution at −78° C. over a period of 30 minutes, followed by 1 hour of stirring at the same temperature. The resulting mixed solution was added dropwise to a 25 mL THF solution of 4.83 g (29.3 mmol) of diethyl chlorophosphite (manufactured by Aldrich) at −78° C. over a period of 30 minutes. After the dropwise addition, a cooling bath was removed and the whole was further stirred at room temperature for 1 hour. After the reaction, THF was removed by evaporation, the residue was dissolved in 50 mL of diethyl ether, and insoluble matter was removed by filtration. The solvent was removed by evaporation and the residue was purified by active alumina column chromatography (eluent: hexane/ethyl acetate=2/1) to obtain the title compound (10.30 g, a pale yellow oily substance). Yield 92%.