Under nitrogen protection, 20 mmol of 4-bromobenzonitrile, 0.2 mmol of palladium acetate, 0.24 mmol of Ph3P and 3 mmol of zinc bromide were dissolved in 30 ml of THF, and then 50 ml of Grignard reagent prepared from 20 mmol of 4-n-heptylbromobenzene was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 2 hours. The reaction mixture was then cooled in an ice-water bath, and 50 ml of a 1% (w/w) dilute salt solution was added dropwise. After the addition was complete, the mixture was stirred for 30 minutes. The organic phase was separated, and the aqueous phase was extracted twice with 50 ml of ethyl acetate. The organic phases were combined, washed twice with 50 ml of water, and the solvent was removed by rotary evaporation to obtain the crude product. The crude product was recrystallized from methanol and decolorized with activated carbon to obtain pure 4'-Heptyl-4-biphenylcarbonitrile. Yield: 68.2%.
