反应详情

To a solution of 1,4,5-trimethyl-1H-imidazole (550 mg, 5 mmol) in dry tetrahydrofuran (15 mL) was added dropwise n-BuLi (3 mL, 2.5 M in hexane) at −40° C. After stirring for 2 h at this temperature, to the solution was added dried DMF (840 mg, 11.5 mmol) at −70° C. The resulting yellow suspension was stirred at −70° C. for 1 h, then at 0° C. for 0.5 h and quenched with ice-water. The mixture was extracted with ethyl acetate, and the organic extracts were dried with Na2SO4 before evaporation to afford an oily residue. The residue was purified by silica column (petroleum ether:ethyl acetate=3:1) to obtain 340 mg of white solid, yield: 50%. 1H-NMR (400 MHz, CDCl3) δ (ppm): 2.21 (s, 1H), 2.25 (s, 1H), 3.90 (s, 1H), 9.66 (s, 1H). LC-MS (ESI) m/z: 138(M+1)+.

1. stirringThe resulting yellow suspension was stirred at −70° C. for 1 h
2. waitat 0° C. for 0.5 h
3. customquenched with ice-water
4. extractionThe mixture was extracted with ethyl acetate
5. dry with materialthe organic extracts were dried with Na2SO4 before evaporation
6. customto afford an oily residue
7. customThe residue was purified by silica column (petroleum ether:ethyl acetate=3:1)