Hydroxyl functionalized ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([2-hydemim][BF₄]) was prepared under microwave irradiation via methylimidazolium, chlorohydrin and sodium tetrafluoroborate as materials. A microwave-assisted solution phase parallel synthesis of 3,4-dihydropyridones was developed using hydroxyl functionalized ionic liquid (IL) as soluble support. Firstly, the [2-hydemim][BF₄] was reacted with ethyl acetoacetate to obtained IL-bound acetoacetate, then this intermediate was reacted with Meldrum acid, ammonium acetate and aromatic aldehyde. Finally 3,4-dihydropyridone derivatives were obtained in good yields and high purities without chromatographic purification after mild cleavage with sodium methoxide in methanol at room temperature, the purity of the target compounds was 95%～98%, and the yield was 83%～93%. The recovered functionalized ionic liquid could be recycled at least six times without losing its activity. It was clear that the solution-phase synthesis using functionalized ionic liquid as supports could be used in the combinatorial chemistry synthesis of 3,4-dihydropyridones derivatives in high efficiency.

Key words: functionalized ionic liquid, dihydropyridone, combinatorial chemistry, parallel synthesis, support