反应详情

A mixture of 2-(chloromethyl)-1-methyl-4-nitro-1H-imidazole (485 mg, 2.76 mmol) and LiBr (4.80 g, 55.2 mmol) in acetone was heated at reflux for 5 hours before all the solvent was removed under reduced pressure. The residue was partitioned between ethyl acetate and water. The aqueous phase was extracted with ethyl acetate twice. The combined organic phase was washed with brine, dried over Na2SO4 and concentrated in vacuo. The crude product was recrystallised from DCM/hexane to give 2-(bromomethyl)-1-methyl-4-nitro-1H-imidazole (105) (576 mg, 95%) as an off-white solid, m.p. 130-132° C. 1H NMR (CDCl3, 400 MHz) δ 7.74 (s, 1H), 4.50 (s, 2H), 3.83 (s, 3H). Analysis found: C, 27.81; H, 3.27; N, 19.05. C5H6BrN3O2.0.04hexane requires: C, 28.16; H, 2.96; N, 18.80. HRMS (FAB+) found: 219.97220, 221.97018 (M+1), calcd. for C5H779/81BrN3O2: 219.97216, 221.97012.

1. temperaturewas heated
2. temperatureat reflux for 5 hours before all the solvent
3. customwas removed under reduced pressure
4. customThe residue was partitioned between ethyl acetate and water
5. extractionThe aqueous phase was extracted with ethyl acetate twice
6. washThe combined organic phase was washed with brine
7. dry with materialdried over Na2SO4
8. concentrationconcentrated in vacuo
9. customThe crude product was recrystallised from DCM/hexane