Preparation and application of 1-benzyl-3-methylimidazole hexafluorophosphate_Industrial additives

Background and overview^[1]

1-Benzyl-3-methylimidazole hexafluorophosphate is an ionic liquid. Ionic liquids have unique solubility properties. They can be used as green solvents to replace environmentally harmful organic solvents commonly used by color paste manufacturers. They can act as solvents and co-catalysts in certain reactions, thereby promoting many chemical reactions to achieve higher yields. and better selectivity. In addition, the solubility of ionic liquids can make the catalyst easy to separate from the product, thereby realizing the recycling of the catalyst.

Preparation^[1]

Add benzyl bromide and methylimidazole in a molar ratio of 1.1:1 into a round-bottomed flask equipped with magnetic stirring, heating device and condensation device, stir and react for 8 hours at 60-90°C, cool and pour Remove the supernatant, wash twice with ethyl acetate, and put it in the refrigerator to solidify for 12 hours; take out the solidified product, add water to dissolve it, and then perform ion exchange with ammonium hexafluorophosphate at a molar ratio of 1:1.2 at room temperature. After the exchange is completed, The product was filtered, washed with water and petroleum ether, and dried in a vacuum oven for later use. 1-Benzyl-3-methylimidazole hexafluorophosphate (PhCH₂MImPF₆): ¹HNMR (CDCl₃ , MHz) δ: 3.99 (s, 3H, NCH2), 5.34 (s, 2H, CH2Ph), 7. Calcium zinc heat stabilizer 11～7.45 (m, 7H, PhH, ImH), 8.59 (s , 1H,ImH).

Applied Research^[1]

Li Jiayun et al. introduced ionic liquids such as 1-benzyl-3-methylimidazole hexafluorophosphate and organic molten salts with ionic liquid characteristics into the hydrogenation reaction, and treated the transition metal compound Rh(PPh₃)₃Cl catalyzes the hydrosilylation reaction of triethylhydrogensilane and unsaturated alkenes, especially styrene. Research has found that the presence of dialkyl imidazole hexafluorophosphate or alkyl pyridine hexafluorophosphate is not only beneficial to improving the catalytic activity of Rh(PPh3)3Cl, but also conducive to the separation of the product and the catalyst after the reaction.