Microwave-assisted synthesis of 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid in one step

Under microwave irradiation,1-butyl-3-methylimidazolium hexafluorophosphate(PF6) ionic liquid was synthesized by one-step method.All reaction factors affecting the yield of the product were investigated.The results showed the optimal reaction conditions as follows: the molar ratio of 1-bromobutane,1-methylimidazole and KPF6 was 1.1∶1∶1.6,the temperature was 70 ℃,the power of microwave was 250 W,the time of microwave irradiation was 15 min,the final yield was 92.7%.The structure of the product was confirmed by IR and 1H NMR analysis.