75-26-3

623577-60-6

General procedure for the synthesis of 4-bromo-1-isopropyl-1H-imidazole from 2-bromopropane: 4-bromo-1H-imidazole (1.0 g, 6.80 mmol) was dissolved in dimethylformamide (5 mL) at 0 °C and sodium hydride (60% oil suspension, 326 mg, 8.20 mmol) was added with stirring. The reaction mixture was gradually warmed to room temperature and stirred continuously for 30 min. Subsequently, 2-bromopropane (0.70 mL, 7.48 mmol) was added slowly and dropwise. The reaction mixture was stirred at room temperature for 15 hours under nitrogen protection. Upon completion of the reaction, the reaction was quenched with water (10 mL) and extracted with ethyl acetate (3 x 15 mL). The organic phases were combined, washed with water (20 mL) and extracted with 1 M hydrochloric acid (3 x 20 mL). The acidic aqueous phases were combined, washed with ethyl acetate (20 mL) and the pH was adjusted to 12 with ammonium hydroxide, followed by extraction with ethyl acetate (3 × 20 mL). The organic phases were combined, dried with anhydrous sodium sulfate, filtered and concentrated. The target product, 4-bromo-1-isopropyl-1H-imidazole, was obtained as a light brown oil (380 mg, 30% yield) by preparative HPLC using an ethyl acetate-isohexane gradient elution.1H NMR (400 MHz, CDCl3) δ: 1.47 (6H, d, J = 6.8 Hz), 4.28-4.32 (1H, m), 6.92 ( 1H, d, J = 1.5 Hz), 7.40 (1H, d, J = 1.5 Hz).MS (ES+) m/z: 189, 191 ([MH]+).