An Economical and Green Synthesis of Spiro[diindeno [1,2-b:2,1-e]pyridine-11,3-indoline]-trione Derivatives through Multi-Component Reaction by Br¢nsted Acidic Ionic Liquid Catalyst.

Synthesis of spiro[diindenopyridine-indoline]-triones by one-pot condensation of 1,3-indandione, isatin and aniline by Brønsted acid ionic liquid (BAIL),1-(4-sulfonicacid)butyl-3-methylimidazolium hydrogen sulfate ([(CH2)4 SO3 HMIM][HSO4]), as reusable and an economical catalyst in water under reflux condition. [ABSTRACT FROM AUTHOR]