Synthesis
The general procedure for the synthesis of 1-butyl-2-methylimidazole from n-butyl bromide and 2-methylimidazole was as follows: 0.82 g of 2-methylimidazole (10 mmol) was dissolved in 20 mL of N,N-dimethylformamide (DMF), heated to 40 °C and then 0.84 g of potassium hydroxide (15 mmol) was added. The reaction mixture was stirred for 15 min, followed by the slow dropwise addition of 1.438 g of n-bromobutane (10.5 mmol). After the dropwise addition was completed, the reaction continued to be stirred at 40 °C for 12 hours. After completion of the reaction, the mixture was cooled to room temperature, diluted with an appropriate amount of water, and then extracted three times with dichloromethane. The organic phases were combined, washed three times with water and dried by adding anhydrous sodium sulfate. The dried organic phase was allowed to stand for 1 hour, followed by diafiltration to remove the desiccant. Finally, the solvent was removed by rotary evaporation to give 1-butyl-2-methylimidazole in 97% yield.
References
[1] Patent: CN108440416, 2018, A. Location in patent: Paragraph 0030; 0031
[2] Journal of Materials Chemistry A, 2014, vol. 2, # 12, p. 4413 - 4421
[3] New Journal of Chemistry, 2012, vol. 36, # 3, p. 702 - 722
[4] Chemical Communications, 2018, vol. 54, # 50, p. 6879 - 6882
[5] Bioscience, Biotechnology and Biochemistry, 2000, vol. 64, # 4, p. 919 - 923
