反应详情

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(S)-2-Amino-3-{(S)-2-[3-(3,4-dichloro-benzyloxy)-phenyl]-2,3-dihydro benzo[1,4]dioxin-6-yl}-propionic acid methyl ester hydrochloride (0.35 g) was taken in 2 mL of EtOAc and cooled to 0° C., NaHCO3 solution (1 mL) and 4-nitrobenzenesulfonyl chloride (178 mg) were added and stirred for 10 minutes. Reaction was stirred at room temperature for 4 hours. EtOAc layer was separated and washed with water and brine, and then dried (Na2SO4), filtered and evaporated. The residue was purified by silica gel column (10% EtOAc in hexanes to 50% EtOAc in hexanes) to get pure (S)-3-{(S)-2-[3-(3,4-dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxin-6-yl}-2-(4-nitro-benzenesulfonylamino)-propionic acid methyl ester (0.37 g). 1H NMR (400 MHz, acetone-d6): 8.33 (m, 2H), 7.89 (m, 2H), 7.73 (d, 1H), 7.62 (d, 1H), 7.37-7.53 (m, 3H), 7.04-7.21 (m, 3H), 6.64-6.72 (m, 3H), 5.22 (s, 2H), 5.09 (m, 1H), 4.35 (m, 1H), 4.21 (m, 1H), 3.97 (m, 1H), 3.61 (s, 3H), 3.03 (m, 1H), 2.76 (m, 1H).

1. customReaction
2. stirringwas stirred at room temperature for 4 hours
3. customEtOAc layer was separated
4. washwashed with water and brine
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. customevaporated
8. customThe residue was purified by silica gel column (10% EtOAc in hexanes to 50% EtOAc in hexanes)