Imidazole → (3-Bromophenyl)-1H-imidazol-2-ylmethanone

Participants

Reaction Steps

A solution of imidazole (2.66 g, 39.1 mmol) and triethylamine (Et3N) 8.03 g, 79.4 mmol) in pyridine at 0° C. is treated with 3-bromobenzoyl chloride (17.5 g, 79.9 mmol), stirred for 5 min, allowed to warm to room temperature for 45 min, treated with an aqueous sodium hydroxide solution (7.5 N, 20 mL, 150 mmol), heated at reflux temperature for 2 h, cooled to room temperature, diluted with water, further cooled with an ice bath for 1 h and filtered. The filtercake is washed with water and dried under vacuum at 50° C. overnight to afford the title compound as a light tan solid, 4.89 g (50% yield), identified by NMR and mass spectral analyses. 1H NMR (500 MHz, CDCl3) δ 10.58 (br s, 1H), 8.73 (t, J=1.8 Hz, 1H), 8.61 (dt, J=7.8, 1.2 Hz, 1H), 7.75-7.72 (m, 1H), 7.42-7.38 (m, 2H), 7.32 (s, 1H); ESI MS m/z 250 [C10H7BrN2O+H]+.

Provenance & Evidence