Synthesis
General procedure for the synthesis of 3-hydroxy-4-iodobenzoic acid from m-hydroxybenzoic acid: 21.0 g (0.52 mol, 1.05 eq.) of sodium hydroxide and 78.7 g (0.52 mol, 1.05 eq.) of sodium iodide were sequentially added to a 700 mL methanol solution containing 69.1 g (0.5 mol, 1 eq.) of 3-hydroxybenzoic acid. The reaction mixture was cooled to 0 °C, followed by slow dropwise addition of aqueous sodium hypochlorite (0.52 mol, 1.05 eq.). The reaction system was kept stirred at 0-5 °C for 2 h, after which stirring was continued overnight at room temperature. Upon completion of the reaction, methanol was removed by evaporation followed by acidification of the reaction mixture with concentrated hydrochloric acid solution. The precipitated product was collected by filtration, washed with water and dried to give 121 g of 3-hydroxy-4-iodobenzoic acid as an off-white solid in 92% yield.
References
[1] Patent: WO2006/18325, 2006, A1. Location in patent: Page/Page column 25-26
[2] Patent: WO2006/18326, 2006, A1. Location in patent: Page/Page column 78
[3] Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1995, # 9, p. 1103 - 1114
[4] Beilstein Journal of Organic Chemistry, 2009, vol. 5,
[5] Journal of the Chemical Society - Perkin Transactions 1, 1999, # 15, p. 2077 - 2086
