159847-71-9

2840-29-1

557-21-1

159847-71-9

Zinc cyanide (11.66 g, 99.4 mmol) and tetrakis(triphenylphosphine)palladium (9.57 g, 8.28 mmol) were sequentially added to a solution of 3-amino-4-bromobenzoic acid (6.0 g, 27.6 mmol) in N,N-dimethylformamide (30 mL) at room temperature. The reaction mixture was heated to 100 °C and maintained at this temperature for 14 hours. Upon completion of the reaction, the mixture was cooled to room temperature, followed by the addition of zinc cyanide (0.65 g, 5.54 mmol) and tetrakis(triphenylphosphine)palladium (1.9 g, 1.64 mmol) again. The mixture was reheated to 100 °C and the reaction was continued for 1 hour. At the end of the reaction, it was cooled to room temperature and the reaction was quenched by adding a mixture of toluene and 1 M ammonia. The organic and aqueous phases were separated and the aqueous phase was extracted with toluene. The organic phases were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/cyclohexane, ratio tapered from 1:2 to 1:0) to afford 3-amino-4-cyanobenzoic acid (2.94 g, 67% yield).