Efficient One-pot pTSA-catalyzed Synthesis of 2-substituted Aryl (indolyl)kojic Acid and Kojyl Thioether Derivatives Under Mild Conditions

New and convenient one-pot syntheses of 2-substituted aryl (indolyl) kojyl thioether from 2-substituted aryl (indolyl) kojic acids have been found. Firstly, the 2-substituted aryl (indolyl) kojic acids were readily obtained from cou- pling of aldehyde, kojic acid and indoles in the presence of p-toluenesulfonic acid as catalyst in good yields and with high selectivity. Then, 2-substituted aryl (indolyl) kojic acids were reacted with thionyl chloride to afford corresponding 2- substituted aryl (indolyl) kojic chlorides. Finally, the 2-substituted aryl (indolyl) kojic chloride derivatives were reacted with benzenethiols in presence of triethylamine in t etrahydrofurane to afford the corresponding thioether derivatives in good yields.