反应详情

6.3 g (35 mmol) of 3-bromo-4-methoxy-3-buten-2-one, 16.7 g acetamidine hydrochloride (175 mmol) and 29.2 ml triethylamine (210 mmol) were combined in 300 ml tetrahydrofuran and heated at reflux for 6 hours. The solvent was removed in vacuo to a crude orange solid. The crude solid was dissolved in 200 ml ethyl acetate and concentrated to 25 ml by boiling off the solvent. Cooling in ice resulted in crystallization of a yellow solid. This was collected by filtration, washed first with ethyl acetate, then with ether and dried at 25° in vacuo to give 9.995 g (23%) of 1-(2-methyl-4-imidazolyl)ethanone, mp 124°-7°. nmr (DMSO-d6) (δ): 4.61 (s, 1H); 1.41 (s, 3H); 1.39 (s, 3H).

1. temperatureheated
2. temperatureat reflux for 6 hours
3. customThe solvent was removed in vacuo to a crude orange solid
4. dissolutionThe crude solid was dissolved in 200 ml ethyl acetate
5. concentrationconcentrated to 25 ml
6. temperatureCooling in ice
7. customresulted in crystallization of a yellow solid
8. filtrationThis was collected by filtration
9. washwashed first with ethyl acetate
10. dry with materialwith ether and dried at 25° in vacuo