7.99 g (60.0 mmol) of 2-chloro-6-fluoropyrazine, 15.08 g (60.0 mmol) of 4-octyloxyphenylboronic acid, 12.78 g (120.0 mmol) of sodium carbonate and 0.72 g (0.6 mmol) of tetrakis(triphenylphosphine)palladium(0) are heated at 80° C. for 2 hours in 400 ml of benzene, 300 ml of ethanol and 150 ml of water. The reaction mixture is partitioned between aqueous sodium chloride solution and ether, the organic phase is washed with aqueous sodium chloride solution, dried over sodium sulfate, filtered and freed from the solvents, and the residue is purified by chromatography (silica gel/hexane: ethyl acetate = 8:2). 17.18 g of 2-fluoro-6-(4-octyloxyphenyl)pyrazine are obtained. ##STR15## 1c
