4-Phenylbutyric acid (20.0 g, 121.8 mmol) was added to a mixed solution of periodate (H5IO6, 5.56 g, 24.4 mmol), iodine (I2, 13.30 g, 52.4 mmol), 10 M sulfuric acid (H2SO4, 5.0 mL), water (36 mL), and acetic acid (166 mL), and the reaction was heated at 70 °C for 19 hours. Upon completion of the reaction, the reaction mixture was cooled and evaporated to dryness. The residue was dissolved in ethyl acetate (EtOAc, 300 mL), washed sequentially with aqueous sodium thiosulfate (Na2S2O3) (2×200 mL) and saturated saline (2×200 mL), dried with anhydrous sodium sulfate (Na2SO4), filtered, and then the solvent was evaporated to give the crude product as a yellow solid. The crude product was recrystallized by ethyl acetate/hexane mixed solvent at 0 °C to afford the target product 4-(p-iodophenyl)butanoic acid as a light yellow solid (15.0 g, 42% yield). The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3): δ11.0 (broad single peak, 1H), 7.61 (double peaks, J = 8.4 Hz, 2H), 6.95 (double peaks, J = 8.0 Hz, 2H), 2.63 (triple peak, J = 7.6 Hz, 2H), 2.38 (triple peak, J = 7.6 Hz, 2H).
