反应详情

2.40 g (19.3 mmol) of 1-(2-methyl-4-imidazolyl) ethanone was dissolved in 30 ml of 48% hydrogen bromide. To the stirred solution at 25° was added over a 5 minute period 3.36 g (21 mmol) of bromine dissolved in 5 ml 48% hydrogen bromide. The reaction was heated to 70° for 2.5 hours and then concentrated in vacuo to a dark oil. A mixture of isopropyl alcohol/ether was added and trituration of the oil gave a solid. This was collected by filtration and washed with ether to give 2.8 g (51%) of 1-(2-methyl-4-imidazolyl)-2-bromoethanone hydrobromide, mp 181° (dec.); nmr (DMSO-d6 (δ): 8.71 (s, 1H); 4.77 (s, 2H); 2.63 (s, 3H).

1. temperatureThe reaction was heated to 70° for 2.5 hours
2. concentrationconcentrated in vacuo to a dark oil
3. additionA mixture of isopropyl alcohol/ether
4. additionwas added
5. customtrituration of the oil gave a solid
6. filtrationThis was collected by filtration
7. washwashed with ether