The general procedure for the synthesis of 2,2'-(1,2-phenylene)diacetic acid from 1,2-phenylenediacetonitrile was as follows: 1,2-phenylenediacetonitrile (5.0 g) was dissolved in 50 mL of concentrated hydrochloric acid and heated and refluxed for 3 hours. After the reaction was completed, 30 mL of water was added and heating was continued overnight. The reaction mixture was cooled to room temperature and washed with ether. Subsequently, the organic layer was extracted twice with aqueous sodium carbonate. The aqueous layers were combined, acidified to pH 2-3 with hydrochloric acid and extracted with ether. The organic phase was dried with anhydrous magnesium sulfate, filtered and concentrated to give 2,2'-(1,2-phenylene)diacetic acid as a light yellow solid in 56% yield with a melting point of 123-125 °C. The product was confirmed by 1H NMR (250 MHz, DMSO-d6): δ 3.58 (s, 4H), 7.20 (s, 4H), 12.34 (br s, 2H); 13C NMR (63 MHz, DMSO-d6): δ 37.1 (2C), 126.8 (2C), 130.6 (2C), 134.1 (2C), 172.4 (2C).
