12 mmol of 7-butoxy-1,8-difluorofluorene-2-boronic acid (Example 6, 1st stage), 20 ml of ethanol, a solution of 24 mmol of sodium carbonate in 20 ml of water and 1 mol % of tetrakis(triphenylphosphine)palladium(0) are added to a solution of 12 mmol of 4-n-pentylbromobenzene in 40 ml of toluene. The mixture is heated to boiling until the reaction is complete. After cooling, the mixture is admixed with 100 ml of water, the phases are separated and the aqueous phase is extracted with toluene. The combined organic phases are washed with saturated NaCI solution and dried over sodium sulfate, and the solvents are removed under reduced pressure. The crude product is chromatographed on silica gel (2:5 dichloromethane/heptane) and recrystallized from heptane. 2-Butoxy-1,8-difluoro-7-(4-n-pentylphenyl)fluorene is obtained.
