overcome this difficulty, we used aqueous hydrotropic solution, which increases the solubility of organic compounds in water by 200-fold. We report an environmentally efficient method for synthesis of pyridopyrimidine carbonitriles and spiro-oxindole dihydroquinazolinones by using 50 % aqueous sodium p-toluene sulfonate (NaPTS) solution at ambient reaction condition. The merits of the present protocol
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