Synthesis of the functionalized spiro[indoline-3,5′-pyrroline]-2,2′-diones via three-component reactions of arylamines, acetylenedicarboxylates, and isatins

In the presence of p-toluenesulfonic acid as the catalyst the three-component reactions of arylamines, acetylenedicarboxylates, and isatins showed very interesting molecular diversity. When equal amount of arylamine was used, the three-component reaction resulted in the high yields of functionalized 3′-hydroxyspiro[indoline-3,5′-pyrroline]-2,2′-dione derivatives. On the other hand the functionalized 3′-N-arylaminospiro[indoline-3,5′-pyrroline]-2,2′-diones were also successfully prepared in satisfactory yields by using 2 M arylamine in the reaction.