ChemInform Abstract: Diethylene Glycol-bis(3-methylimidazolium) Dihydroxide as a Dicationic Ionic Liquid Catalyst for the Synthesis of 4H-Pyrane Derivatives in Aqueous Medium

Diethylene glycol-bis(3-methylimidazolium) dihydroxide [DiEG(mim) 2 ][OH] 2 was prepared by the reaction between sodium hydroxide and diethylene glycol-bis(3-methylimidazolium) dibromide in aqueous ethanol at room temperature. This solid, quaternized ionic liquid was employed as a recyclable catalyst for the synthesis of 4 H -pyrane derivatives in high yields from the three-component condensation reaction of malononitrile, aromatic aldehydes, and 1,3-dicarbonyls in water at room temperature. In addition, spiropyrane derivatives were synthesized from the reaction of isatin, malononitrile, and 1,3-dicarbonyls in water at reflux. The dicationic ionic liquid showed the same efficiency when used in consecutive reactions.