反应详情

温度

65 °C

To a solution of 4-bromoaniline (8.6 g, 50 mmol) in MeOH (100 mL) was added ethyl glyoxalate (12 mL, 60 mmol, 50% in toluene) and the resulting mixture heated at reflux for 3.5 h. The mixture was then concentrated in vacuo and the resulting residue reconstituted in anhydrous ethanol (100 mL) and treated with tosylmethyl isocyanide (14.6 g, 75 mmol) and potassium carbonate (13.8 g, 100 mmol). The resulting mixture was heated at 65° C. for 4 h, then cooled to rt and poured to water (500 mL) and the resulting solid collected by filtration. The crude material thus isolated was crystallized from ethyl acetate/hexane to give pure 3-(4-bromophenyl)-3H-imidazole-4-carboxylic acid ethyl ester (4). MS (ES+): m/z 295/297 (1/1) [MH+]. 1H NMR (CDCl3, 400 MHz): δ=1.27 (t, J=7.1 Hz, 3H), 4.22 (q, J=7.1 Hz, 2H), 7.22 (d, J=8.7 Hz, 2H), 7.61 (d, J=8.7 Hz, 2H), 7.65 (d, J=0.9 Hz, 1H) and 7.85 (d, J=0.9 Hz, 1H).

1. temperaturethe resulting mixture heated
2. temperatureat reflux for 3.5 h
3. concentrationThe mixture was then concentrated in vacuo
4. temperaturecooled to rt
5. filtrationthe resulting solid collected by filtration
6. customThe crude material thus isolated
7. customwas crystallized from ethyl acetate/hexane