With palladium 10% on activated carbon; hydrogen In methanol for 16 h;
A mixture of imidazolium hydrochloride (82-Cl) (11.00 g, 65.8 mmol), 10percent Pd(C) (2 g) and methanol (200 mL) was hydrogenated at 60 psi of H2 for 16 hours. The solid was filtered off using a Celite pad, and the solvent was removed under reduced pressure to give 4,5-dimethylimidazolium hydrochloride (82) (8.02 g, 92percent yield).
EXAMPLE 1 Diacetyl (2.66 g, 0.031 mole) was added to concentrated (6 N) hydrochloric acid (20 ml) with stirring. Methylene diformamide (3.0 g, 0.029 mole) was then added in small portions over about ten minutes, and the reaction mixture stirred at room temperature for two hours. The solution was then evaporated to dryness, the residue washed with acetone and the solid hydrochloride removed by filtration. Yield was 3.2 g of 4,5-dimethylimidazole hydrochloride (82% based on methylene diformamide) N.M.R. and I.R. spectra were consistent with structure and purity by High Pressure Liquid Chromatography (HPLC) was 100%.
1-(2-((tert-butyldimethylsiIyl)oxy)ethyl)-4,5-dimethyl-1H-imidazole[ No CAS ]
Operation in experiment
Step 1 : l-(2-((tert-butyldimethylsiIyl)oxy)ethyl)-4,5-dimethyl-lH-imidazole  A solution of 4,5-dimethyl- lH-imidazole hydrochloride (2.94 g, 22.2 mmol) was in N,N-dimethylformamide (30.0 mL, 387 mmol) was cooled to 0 C. Sodium hydride (3.55 g, 88.7 mmol) was slowly added and the solution was stirred for 30 mins at 0 C. Potassium iodide (4.417 g, 26.61 mmol) and (2-bromoethoxy)-tert-butyldimethylsilane (6.365 g, 26.61 mmol) were added and the mixture was allowed to warm to room temperature with stirring over 30 minutes. The reaction as quenched with methanol (3 mL) and diluted with water ( 150 ml). The resulting aqueous mixture was extracted with ethyl acetate (3 x 70 mL). The combined organic portions was washed with brine, dried over Na2S04, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (0 to 15% MeOH in EtOAc) to provide 4.34g (77%) of the title compound. NMR (400 MHz, Chloroform-<i) delta 7.33 - 7.39 (m, 1 H) 3.87 - 3.93 (t, 2 H) 3.73 - 3.84 (t, 2 H) 2.13 - 2.18 (s, 3 H) 2.12 (s, 3 H) 0.85 (s, 9 H) -0.04 (s, 6 H).
With potassium hydroxide; In dimethyl sulfoxide; at 40℃; for 16h;Inert atmosphere;
A solution of <strong>[53316-51-1]4,5-dimethylimidazolium hydrochloride</strong> (82) (8.00 g, 60.3 mmol) in anhydrousDMSO (100 mL) was treated with solid 90% KOH (11.20 g, 180 mmol) and bromoethane (4.9 mL, 65mmol). The obtained mixture was stirred under argon and heated at 40C for 16 hours. The reaction mixture was poured into ice-water (500 mL), treated with SN NaOH and extracted with DCM/THF (9:1, 2 x 200 mL). The extract was washed with water (100 mL), dried over Na2CO3, and the solvent was removed under reduced pressure to give 1-ethyl-4,S-dimethylimidazole (87-0) (5.43 g, 73% yield).
With palladium 10% on activated carbon; hydrogen; In methanol; under 3102.97 Torr; for 16h;
A mixture of imidazolium hydrochloride (82-Cl) (11.00 g, 65.8 mmol), 10% Pd(C) (2 g) and methanol (200 mL) was hydrogenated at 60 psi of H2 for 16 hours. The solid was filtered off using a Celite pad, and the solvent was removed under reduced pressure to give 4,5-dimethylimidazolium hydrochloride (82) (8.02 g, 92% yield).
4,5-dimethyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazole[ No CAS ]
Operation in experiment
A solution of <strong>[53316-51-1]4,5-dimethyl-1H-imidazole hydrochloride</strong> (2.0 g, 15.08 mmol) in DMF (20 mL) was added NaH (60 wt %, 908 mg, 22.63 mmol) in portions at 0 C. under N2. The resulting mixture was stirred for 0.5 h at 0 C. under N2, To the above mixture was added SEM-Cl (3.77 g, 22.63 mmol) dropwise at 0 C. The resulting mixture was stirred for additional 1 h. The reaction was quenched with water (50 mL) at 0 C., then extracted with EtOAc (100 mL×2), washed with brine (50 mL×2), dried and concentrated. The crude residue was purified by reverse phase C18 column chromatography (MeCN/H2O) to give the desired compound (5.12 g, 81.1%) as a yellow oil. ESI-MS m/z 227.10 [M+H]+.