Tetramethylimidazolium iodide and 1,3,4,5-tetramethylimidazolium bis(trifluoromethane)sulfonimide were prepared according to a published procedure97. IV. Synthetic procedures NMR Characterization. 400 MHz 1H, 101 MHz 13C and 376 MHz 19F NMR spectra were recorded on a Bruker Avance III 400 NMR spectrometer in CD3CN. Solvent residual signals with chemical shifts of 1.94 ppm (1H NMR) and 118.69 ppm (13C NMR) were used as reference. For DMSO-d6, a chemical shift of 39.52 ppm was taken as a reference in 13C NMR measurements. 1,3-Dimethyl-4,5-dichloroimidazolium iodide. 4,5-Dichloroimidazole (10.67 g, 77.90 mmol) was dissolved in CH3CN (150 mL) in a 500 mL round bottom flask equipped with a reflux condenser. Sodium hydrogen carbonate (9.82 g, 116.9 mmol) and excess iodomethane (20 mL, 0.321 mol) were added and the mixture was stirred at 85 °C under N2 for 48 h. Iodomethane and CH3CN were removed using a rotary evaporator. To the solid residue, CH3CN (150 mL) was added to redissolve the imidazolium iodide. After stirring, the formed salts were left to settle. The clear solution was transferred to a 1L round bottom flask and the remaining solids were washed with CH3CN (3x50 mL). Evaporation of CH3CN from the combined solutions yielded 4,5-dichloro-1,3-dimethylimidazolium iodide (22.36 g, 98%). Of this batch, 6.32 g was dissolved in CH3CN (50 mL), requiring slight warming (40 °C). Diethyl ether (200 mL) was added under stirring, producing a white precipitate. The solvent was removed by syringe, the solids were washed three times with diethyl ether (3x100 mL) which was also removed and the remaining solid was dried under vacuum. Yield 6.13 g (97%). 1H NMR (400 MHz, CD3CN): 9.29 (s, 1H, 2-H), 3.83 (s, 6H, 1+3-CH3). 13C NMR (101 MHz, CD3CN): 137.18 (2-C), 121.00 (4+5-C), 36.49 (1+3-C).
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