| 摘要 |
PURPOSE:To obtain the title compound in high yield and purity, by heating a solution of 0-chlorobenzoic acid in a solvent containing chlorosulfonic acid which absorbed chlorine in the presence of iodine, a compound containing it, or their mixture as a catalyst. CONSTITUTION:Chlorine is absorbed in 0-chlorobenzoic acid dissolved in chlorosulfonic acid (C) or a solvent containing C, and heated in the presence of iodine, a compound containing it, or their mixture, to give 2,5-dichlorobenzoic acid. The solvent containing C is preferably C alone or its mixture with sulfuric acid. Preferably, the compound containing iodine is a metallic iodide, e.g. potassium iodide, and its mixture contains iodine or a metallic iodide and another chlorine carrier, e.g. ferric chloride. |
