反应详情

A solution of 1.57 g (12.6 mmol) of 5-acetyl-4-methylimidazole in 15 ml of concentrated hydrobromic acid was warmed to 50° and a solution of 2.01 g (12.6 mmol) of bromine in 15 ml of concentrated hydrobromic acid was added over 0.75 hour. The mixture was stirred at 50° for 1.25 hour, then concentrated. The residue was triturated with isopropyl alcohol and the white solid was collected by filtration. This amounted to 2.78 g (78%) of 1-(4-methyl-5-imidazolyl)-2-bromoethanone hydrobromide: nmr (D6DMSO) (δ): 9.40 (s, 1H); 4.87 (s, 2H); 2.65 (s, 3H). This material was converted to its free base by stirring for 15 minutes in 50 ml of saturated sodium bicarbonate solution to give, after collection by filtration and drying, 1-(4-methyl-5-imidazolyl)-2-bromoethanone as a white powder.

1. concentrationconcentrated
2. customThe residue was triturated with isopropyl alcohol
3. filtrationthe white solid was collected by filtration
4. stirringby stirring for 15 minutes in 50 ml of saturated sodium bicarbonate solution
5. customto give
6. customafter collection
7. filtrationby filtration
8. customdrying