A mixture of methyl 2-amino-5-bromobenzoate (50 g, 217 mmol) and cuprous cyanide (19.7 g, 220 mmol) was heated to reflux (ca. 200 °C) in 200 mL of N-methyl-2-pyrrolidinone and reacted overnight, followed by cooling to room temperature. The dark reaction mixture was slowly poured into 1800 mL of ether under vigorous stirring. The dark viscous oily material at the bottom was separated and discarded, and the upper turbid solution was washed sequentially with 200 mL of saturated saline, 200 mL of 1 M sodium hydroxide solution, and twice with 200 mL of saturated saline (total 2000 mL). The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness under reduced pressure to give about 20 g of a yellow solid, methyl 2-amino-5-cyanobenzoate crude, in 52% yield.
