Ethyl 4-bromo-2,5-diethoxybenzoate (0.615 g, 1.94 mmol), zinc cyanide (0.137 g, 1.17 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.157 g, 0.136 mmol) were combined under nitrogen in a flame-dried Schlenk tube. Dimethylformamide (7 mL) was added and the reaction mixture was put through three freeze-pump-thaw cycles and then put under a nitrogen atmosphere and heated at 80° C. for 16 h. After cooling to room temperature, water (50 mL) was added and the resulting mixture was extracted with diethyl ether (100 mL, 2×50 mL). The combined organic phases were washed with brine (3×50 mL) and then dried over magnesium sulfate and concentrated. Purification of the crude residue by flash column chromatography (silica gel, eluting with 33% ethyl acetate in hexanes) gave ethyl 4-cyano-2,5-diethoxy-benzoate as an off-white solid (0.416 g, 81%).
