反应详情

To a mixture of N-(tert-butoxycarbonyl)-O-ethylserine (5.3 g, 22 mmol) and potassium carbonate (6.3 g, 45 mmol) in DMSO (80 mL) was added iodomethane (6.5 g, 45 mmol) at room temperature. After 12 hours, the mixture was diluted with water and extracted with ethyl acetate. The combined organic layers were dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified via chromatography on silica gel to afford methyl N-(tert-butoxycarbonyl)-O-ethylserinate. MS ESI calc'd. for C11H22NO5 [M+H]+ 248. found 248. 1H NMR (400 MHz, CDCl3) δ 5.36 (d, J=8.0 Hz, 1H), 4.42-4.39 (m, 1H), 3.84-3.81 (m, 1H), 2.75 (s, 3H), 3.64-3.60 (m, 1H), 3.49-3.45 (m, 2H), 1.45 (s, 9H), 1.15 (t, J=7.2 Hz, 3H).

1. extractionextracted with ethyl acetate
2. dry with materialThe combined organic layers were dried over sodium sulfate
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. customThe residue was purified via chromatography on silica gel