The general procedure for the synthesis of 3-iodo-4-methylbenzoic acid from methyl 3-iodo-4-methylbenzoate was as follows: methyl 3-iodo-4-methylbenzoate (3 g, 10.9 mmol, 1 eq.) was dissolved in methanol (30 mL), followed by addition of sodium hydroxide (1.3 g, 32.7 mmol, 3 eq.) and water (15 mL). The reaction mixture was stirred at room temperature for 14 hours. Upon completion of the reaction, the solution was concentrated under reduced pressure and subsequently diluted with the addition of water. The pH of the reaction mixture was adjusted with concentrated hydrochloric acid to 3. The precipitated solid was collected by filtration and dried under reduced pressure to afford the target product 3-iodo-4-methylbenzoic acid in a yield of 2.7 g (96% yield). The 1H NMR (400 MHz, DMSO-d6) data of the product were as follows: δ 2.44 (s, 3H), 7.45 (d, J=8.00 Hz, 1H), 7.85 (d, J=3.18 Hz, 1H), 8.31 (s, 1H).
