General procedure for the synthesis of 1,2,3,4-tetrahydroquinoline-6-carbonitrile from 6-bromo-1,2,3,4-tetrahydroquinoline and zinc cyanide: To a solution of 6-bromo-1,2,3,4-tetrahydroquinoline (10 g, 47.15 mmol) in N,N-dimethylformamide (80 mL) was added tetrakis(triphenylphosphine)palladium (2.8 g, 2.42 mmol) and zinc cyanide (6.4 g, 54.49 mmol), and the reaction was stirred at 120 °C in an oil bath for 2 hours. After the reaction was completed, the reaction was quenched by adding water (400 mL), and the organic layer was extracted with dichloromethane (3×50 mL), the organic phases were combined and concentrated in vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography with the eluent being a petroleum ether solution of 1%-20% ethyl acetate to afford 1,2,3,4-tetrahydroquinoline-6-carbonitrile as a yellow solid (6 g, 80% yield).LC/MS (ESI, m/z): [M + H]+ 159.1.1.1H-NMR (300 MHz, CDCl3) δ7.20-7.23 (m , 2H), 6.40 (d, J = 8.1 Hz, 1H), 3.36-3.40 (t, J = 5.7 Hz, 2H), 2.72-2.77 (t, J = 6.3 Hz, 2H), 1.90-1.97 (m, 2H).
