反应详情

4,5-Dimethoxy-2-nitrobenzyl carbonochloridate (394 mg, 1.43 mmol) was added to a solution of (R)-3-(ethyldisulfanyl)-2-(methylamino)propanoic acid (Compound 2f-F) (232 mg, 1.19 mmol) and sodium carbonate (252 mg, 2.38 mmol) in dioxane (3 ml) and water (3 ml), and the mixture was stirred at room temperature for 30 minutes. A saturated aqueous ammonium chloride solution (3 ml) was added to the reaction mixture, after which the mixture was extracted with ethyl acetate and the organic layer was washed with water. The organic extract was then dried over magnesium sulfate. Following concentration under reduced pressure, the resulting residue was purified by reverse-phase silica gel column chromatography (10 mM aqueous ammonium acetate solution/methanol=70/30→0/100) to afford (R)-2-((((4,5-dimethoxy-2-nitrobenzyl)oxy)carbonyl)(methyl)amino)-3-(ethyldisulfanyl)propanoic acid (Compound 2k-F) (483 mg, 93%).

1. extractionafter which the mixture was extracted with ethyl acetate
2. washthe organic layer was washed with water
3. extractionThe organic extract
4. dry with materialwas then dried over magnesium sulfate
5. concentrationconcentration under reduced pressure
6. customthe resulting residue was purified by reverse-phase silica gel column chromatography (10 mM aqueous ammonium acetate solution/methanol=70/30→0/100)