Carbon tetrabromide → 5-Bromo-1-methyl-2-(2-methyl-imidazol-1-ylmethyl)-1H-imidazole

Participants

Reaction Conditions

Reaction Steps

(5-Bromo-1-methyl-1H-imidazol-2-yl)-methanol (1.0 g, 5.24 mmol) and tetrabromomethane (2.48 g, 7.33 mmol) were dissolved in THF (10.0 ml) and cooled to 0° C. Triphenylphosphine (1.98 g, 7.33 mmol) was added portionwise over a period of 30 min. The reaction mixture was stirred at 0° C. for 1 h to provide a white suspension. In a second flask, NaH (1.05 g, 26.18 mmol, 60% in mineral oil) was suspended in DMF (20 ml) and cooled to 0° C. 2-Methylimidazole (2.15 g, 26.2 mmol) was added portionwise. The reaction mixture was stirred at 60° C. for 30 min, cooled to 0° C. and treated with the above suspension. After 2 h stirring at room temperature, the reaction mixture was quenched with aqueous saturated NaHCO3 solution (50 ml). The aqueous layer was extracted 3 times with AcOEt. The combined extracts were dried over Na2SO4, filtered and the solvent was removed in vacuo. The residue was chromatographed (silica, elution with CH2Cl2/MeOH=95:5) to provide the title compound (0.7 g, 52%) as a brown solid. MS: m/e=255.0 (M+).

Provenance & Evidence