| 摘要 |
PURPOSE:To produce O,O'-diacyltartaric acid anhydride in high purity and yield at a low cost by reacting a specific aromatic carboxylic acid with tartaric acid in the presence of a chlorinating agent and a catalyst. CONSTITUTION:The objective O,O'-diacyltartaric acid anhydride of formula II can be produced by reacting (A) an aromatic carboxylic acid of formula I (R<1> and R<2> are H, a halogen or a 1-3C alkyl) with (B) tartaric acid in the presence of (C) a chlorinating agent (preferably thionyl chloride) and (D) a catalyst (preferably a Lewis acid selected from ferric chloride, zinc chloride, aluminum chloride and boron trifluoride) at 40-170 deg.C (preferably 60-150 deg.C). The molar ratio of the component A to the component B is 1.8-4, preferably 2.0-2.4 and that of the component C to the component A is 1.4-3, preferably 1.5-2.0. The amount of the component D is 0.001-0.2mol, preferably 0.002-0.10mol based on 1mol of the component B. |
