Study On The Reaction Of Knoevenagel Condensation And Michaeladdition In Pyrazolium-based Ionic Liquid

Pyrazolium-based ionic liquids have been widely used in electrochemical research due to their stable chemical properties,good solubilities,non-volatile physical properties and excellent electrochemical properties.But their application to organic reactions,which is less studied till now,is worth looking forward to the respect.In this paper,the utilization of pyrazolium-based ionic liquids in Knoevenagel condensation and Michael addition is studied.The main contents are as follows:1.Synthesis of pyrazolium-based ionic liquid.2-n-butyl-1,3,5-trimethylpyrazoateAcetate [BTMPz][AcO] was prepared by Knor reaction of acetyl acetone and methyl hydrazine,followed by a nucleophilic substitution of n-butyl bromide and an anion exchange reaction.The stucture was characterized by NMR and IR.2.Knoevenagel condensation reaction in [BTMPz][AcO][BTMPz][AcO] ionic liquid was used as reaction medium for Knoevenagel condensation reaction.The experimental results showed that the ionic liquid exhibited good catalytic effect and good universality.The condensation time was short and conversion rate was high.The ionic liquid had been recycled efficiently.3.Michael addition reaction in [BTMPz][AcO]/NaOHThe experimental results showed that the Michael addition rate could be accelerated in ionic liquid [BTMPz][AcO],and the reaction time was short and the yields were high.The method has the advantages of high separating efficiency and convenient operation.The ionic liquid could be reused many times.