A suspension of ethyl 5-(4-bromo-2-formylphenoxy)pentanoate (9.0 g) and 4-(2-butoxyethoxy)phenylboric acid (7.8 g) and potassium carbonate (9.1 g) in toluene (100 ml), ethanol (10 ml) and water (10 ml) was stirred under an argon atmosphere for 30 minutes. After addition of tetrakis(triphenyl)phosphine palladium (1.6 g), the solution was heated at 100° C. for 12 hours under an argon atmosphere. The solution was allowed to cool. Water was added and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated saline and dried over magnesium sulfate. The solvent was distilled off under reduced pressure to obtain brown amorphous ethyl 5-[[4′-(2-butoxyethoxy)-3-formyl [1,1′-biphenyl]-4-yl]oxy]pentanoate (12.0 g).
