4'-Methyl-2-cyanobiphenyl is prepared by the reaction of o-cyanobromobenzene and potassium (4-methylphenyl)trifluoroborate. The specific synthesis steps are as follows:
General procedure: A mixture of aryl halide (0.5 mmol), potassium aryltrifluoroborate (0.6 mmol), K2CO3 (1.0 mmol), Pd/C (5%; 0.5 mol%), ethanol (3 mL), and distilled water (1 mL) was stirred at 80 °C in air for the time indicated.
The reaction mixture was added to brine (15 mL) and extracted with ethyl acetate (4×15 mL).
The organic solvent was removed under vacuum, and the product was isolated by short-column chromatography.