A solution of 4.5 g of 4-propylphenylboric acid obtained by reaction of a Grignard reagent prepared from 4-propylbromobenzene and magnesium with trimethoxy borane and subsequent hydrolysis with dilute hydrochloric acid, 5.0 g of 6-bromo-2-(3,4-difluorophenyl)-1,2,3,4-tetrahydronaphthalene synthesized in the example 15, 0.3 g of tetrakis(triphenylphosphine)palladium(0), and 3.0 g of potassium phosphate in 30 ml of dimethyl formamide was stirred for 10 hours at 80° C. The mixture was subsequently cooled to room temperature, water was added, and the mixture was extracted with toluene. The organic layer was washed with a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and then concentrated. The residue was purified by silica gel column chromatography (hexane) and then recrystallized from ethanol, and yielded 4 g of 2-(3,4-difluorophenyl)-6-(4-propylphenyl)-1,2,3,4-tetrahydronaphthalene. This compound displayed a purity of 99.7% when analyzed by gas chromatography, and had a molecular weight of 362.
