A mixture of 2.0 g (7.33 mmol) of 2-bromoselenophene (purity 92%), 51 mg (0.07 mmol) of bis(triphenylphosphine)palladium(II) chloride, 10 μl (0.2 mmol) of hydrazine hydrate (80%) and 5 ml (5.0 mmol) of aqueous sodium metaborate soln. (1 M) is heated to 60° C. A soln. of 2.11 g (8.1 mmol) of 3-fluoro-4′-propylbiphenyl-4-ylboronic acid in 6 ml of THF is slowly metered in, and the batch is stirred at this temperature for 3 h. After cooling, the mixture is diluted with n-heptane, and the organic phase is separated off. The aqueous phase is extracted with n-heptane, and the combined organic phases are dried using sodium sulfate. The solution is concentrated, and the precipitate forming is filtered off. The residue is purified by column chromatography (SiO2, n-heptane). The further purification is carried out by recrystallisation from n-heptane and from ethanol.
