反应详情

温度

-20 °C

Combine 2,4,5-tribromoimidazole (15.29 g, 0.050 mol), cesium carbonate (18.0 g, 0.055 mol), benzyl bromide (6.3 mL, 0.053 mol) and dimethylformamide (100 mL) and stir at 20° C. for 18 hours. Filter solids and concentrate under reduced pressure. Suspend in dichloromethane, filter through 2 cm pad silica gel and wash with dichloromethane (1 L). Concentrate filtrates under reduced pressure. Redissolve in dichloromethane (15 mL), add 4 M HCl in dioxane (12.5 mL, 0.050 mol), cool to −20° C. and filter solids. Concentrate filtrate, dissolve in ethyl ether, add 1 M HCl/ether (20 mL) and hexane (40 mL), cool −20° C. and filter. Combine solids and dry under reduced pressure to give 19.6 g (90%, 0.045 mol) of the title compound. MS(ES+): m/z=393.0 (M+H)+

1. filtrationFilter solids
2. concentrationconcentrate under reduced pressure
3. filtrationfilter through 2 cm pad silica gel
4. washwash with dichloromethane (1 L)
5. dissolutionRedissolve in dichloromethane (15 mL)
6. filtrationfilter solids
7. dissolutionConcentrate filtrate, dissolve in ethyl ether
8. additionadd 1 M HCl/ether (20 mL) and hexane (40 mL)
9. temperaturecool −20° C.
10. filtrationfilter
11. customCombine solids and dry under reduced pressure