反应详情

Methyl 4-ethoxycarbonyl-3-oxopentanoate (200 ml; 1.06 mmole) was dissolved in dry methanol (2.5 ml), and benzylamine (386 mg; 3.6 mmole) and molecular sieve 3A (0.3 g) were added thereto. A solution of acetyl chloride (170 mg; 2.17 mmole) in dry methanol (0.9 ml) was added to the resultant mixture, followed by allowing to stand at room temperature for 16 hours. Molecular sieve was removed by filtraton, and the filtrate was diluted with ethyl acetate, washed successively with a saturated sodium bicarbonate solution and water, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was dissolved in toluene (2.5 ml). Gaseous ketene was introduced therein at room temperature. After completion of the reaction, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography to give methyl ethyl 2-acetyl-3-benzylamino-4-methyl-2-pentenedioate.

1. customMolecular sieve was removed by filtraton
2. additionthe filtrate was diluted with ethyl acetate
3. washwashed successively with a saturated sodium bicarbonate solution and water
4. dry with materialdried over anhydrous sodium sulfate
5. concentrationconcentrated under reduced pressure
6. dissolutionThe residue was dissolved in toluene (2.5 ml)
7. additionGaseous ketene was introduced
8. customat room temperature
9. customAfter completion of the reaction
10. customthe solvent was removed under reduced pressure
11. customthe residue was purified by silica gel column chromatography