反应详情

To p-nitrophenylalanine methyl ester hydrochloride (5 g, 0.019 mole) (Lancaster) in THF (80 mL) and triethylamine (3.88 g, 0.038 mole) was added isobutylchloroformate (2.62 g, 0.019 mole) (Sigma) dropwise at ice bath temperature. The reaction was stirred at room temperature for 3.5 hours. The resulting precipitate was filtered and washed with THF. The solvent from the filtrate was removed under vacuum. The residue was taken up in ethyl acetate. The ethyl acetate portion was worked up with saturated NaHCO3 (1×), H2O (1×), 1N HCl (2×), H2O (2×), dried over MgSO4 and removed under vacuum to yield 5.08 g of p-nitro-phenylalanine methyl ester, N-isobutylcarbamate as a yellow solid.

1. filtrationThe resulting precipitate was filtered
2. washwashed with THF
3. customThe solvent from the filtrate was removed under vacuum
4. dry with materialdried over MgSO4
5. customremoved under vacuum