An Environmental Friendly Approach for the Synthesis of Spiro[indoline-3′,2-quinazoline]2′,4(3<i>H</i>)-dione Using 1-Methylimidazolium Hydrogen Sulfate, as Reusable Catalyst
A facile and environmentally benign procedure for the synthesis of 3‐aryl‐1H‐spiro[indoline‐3′,2‐quin‐azoline]2′,4(3H)‐dione from isatoicanhydride, aromatic amines and isatin derivatives in Brønsted acidic ionic liquid, 1‐methylimidazolium hydrogen sulfate, was reported. The ability to reuse the ionic liquid, the high yield, short reaction time and ease of purification are the important features of