反应详情

Sodium hydride (327 mg, 13.6 mmol) ws added to a solution of methyl 1-(2,4-dimethoxybenzyl)-5-oxopyrrolidine-3-carboxylate (2.0 g, 6.8 mmol) in THF (50 mL) at 0° C. The mixture was stirred at room temperature for 2 hours. Then the mixture was added methyl iodide (4.8 g, 34 mmol) dropwise at 0° C. The mixture was stirred at room temperature for 16 hours and then was diluted with water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue purified by chromatography on silica gel (ethyl acetate/petroleum ether) to give methyl 1-(2,4-dimethoxybenzyl)-3-methyl-5-oxopyrrolidine-3-carboxylate. MS ESI calc'd. for C16H22NO5 [M+H]+ 308. found 308. 1H NMR (400 MHz, CD3OD): δ 7.11 (d, J=8.8 Hz, 1H), 6.56 (s, 1H), 6.50 (d, J=8.8 Hz, 1H), 4.39 (s, 2H), 3.82 (s, 3H), 3.80 (s, 3H), 3.68 (s, 3H), 3.64 (d, J=16.8 Hz, 1H), 3.10 (d, J=16.8 Hz, 1H), 2.93 (d, J=16.8 Hz, 1H), 2.32 (d, J=16.8 Hz, 1H), 1.33 (s, 3H).

1. stirringThe mixture was stirred at room temperature for 16 hours
2. extractionextracted with ethyl acetate
3. dry with materialThe organic layer was dried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe residue purified by chromatography on silica gel (ethyl acetate/petroleum ether)