反应详情

Add sodium hydride (0.79 g; 1.1 equiv; 19.75 mmoles) slowly to a 0° C. solution of 1H-imidazole-1-ethanol (2.01 g; 1.0 equiv; 17.93 mmoles) in tetrahydrofuran (90 mL). Stir for 1 hour, then add acetic acid, bromo-, 1,1-dimethylethyl ester (4.03 mL; 1.49 equiv; 26.76 mmoles) dropwise at 0° C. Warm the solution to ambient temperature and stir for 3 hours, then add 250 mL saturated aqueous sodium bicarbonate solution. Extract the mixture with dichloromethane (3×150 mL). Wash the combined organic extracts with brine (100 mL), dry over sodium sulfate, filter, and concentrate to afford the crude product. Purify this residue by column chromatography (0 to 20% methanol in dichloromethane) to afford tert-butyl 2-(2-imidazol-1-ylethoxy)acetate (0.85 g; 21%) as a viscous yellow-brown oil: MS (m/z): 227(M+1).

1. customdropwise at 0° C
2. stirringstir for 3 hours
3. extractionExtract the mixture with dichloromethane (3×150 mL)
4. washWash the combined organic extracts with brine (100 mL)
5. dry with materialdry over sodium sulfate
6. filtrationfilter
7. concentrationconcentrate
8. customto afford the crude product
9. customPurify this residue by column chromatography (0 to 20% methanol in dichloromethane)