反应详情

Dihydropyran (2.27 ml) and p-toluenesulfonic acid (500 mg) were added to a suspension of N-benzyloxycarbonyl-DL-serine (5 g) in chloroform, and the mixture was stirred at room temperature overnight under argon. Triethylamine (11.65 ml), ethyl p-aminophenylacetate hydrochloride (4.5 g) and 2-chloro-1-methylpyridinium iodide (6.4 g) were added to the reaction mixture and the whole was refluxed for 3 hours. The reaction mixture was concentrated under reduced pressure. The residue was dissolved in ethyl acetate, washed with 1N HCl, 5% NaHCO3, and saturated saline solution, and dried over Na2SO4. The solvent was evaporated under reduced pressure. The residue was purified by column chromatography (silica gel=300 g, hexane/ethyl acetate=20/9) to obtain (RS)-2-(benzyloxycarbonylamino)-N-(4-(ethoxycarbonylmethyl)phenyl)-3-(tetrahydropyran-2-yloxy)propanamide (6.847 g).

1. temperaturethe whole was refluxed for 3 hours
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. dissolutionThe residue was dissolved in ethyl acetate
4. washwashed with 1N HCl, 5% NaHCO3, and saturated saline solution
5. dry with materialdried over Na2SO4
6. customThe solvent was evaporated under reduced pressure
7. customThe residue was purified by column chromatography (silica gel=300 g, hexane/ethyl acetate=20/9)