Mild and Efficient Synthesis of Isoindigo Derivatives Catalyzed by Lewis Acid

Abstract A mild and efficient ZrCl 4 -catalyzed synthesis of isoindigo derivatives from isatins and indolin-2-ones in refluxing ethanol is described. A variety of new functionalized isoindigo derivatives are obtained by simple filtration. Lewis acid was first used as catalyst in the synthesis of isoindigo derivatives.