synthesis of 4-chloroquinoline-2-carbonitrile: To a solution of 2,4-dichloroquinoline (444 mg, 2.24 mmol) in DMF (5 mL) was added zinc cyanide (117 mg, 1.14 mmol) and Pd(PPh3)4 (259 mg, 0.22 mmol). The reaction mixture was stirred at 120 °C for 1 h. A saturated NH4Cl solution (20 mL) was added and the mixture was extracted with ethyl acetate (3x5 mL). The organic layer was washed with a NaCl solution (5mL) and dried over sodium sulfate, filtered and evaporated. The product was further purified by chromatography on silica gel eluting with cyclohexane/ethyl acetate (95:5) to give 4-chloroquinoline-2-carbonitrile (392 mg, 2.085 mmol, 93 %) as a white solid.
