Hmim][HSO4]: An Efficient and Reusable Catalyst for the Synthesis of Spiro[dibenzo[a,i]-xanthene-14,3'-indoline]-2',8,13-triones and Spironaphthopyran[2,3-d]pyrimidine-5,3'-indolines

Abstract

These activities, combined with diverse chemicalbehavior make quinones attractive targets in organic syn-thesis.The removal of volatile organic solvents in organic reac-tions is the most important goal in green chemistry. One ofthe most efficient protocols to reach this aim is replacementof the volatile solvents with ionic liquids possessing lowvolatility, high thermal stability, non-flammability, recycl-ability and unique catalytic activity. During recent years,ionic liquids have attracted interest as environmentallybenign reagents due to their favorable properties and avariety of catalytic reactions have been successful usingionic liquids.