1,2-Dichloroethane → Benzyl-2-{2-[5-(tert-butoxycarbonyl)-4-oxopentanamido]-acetamido}-acetate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

2-[2-(tert-butoxycarbonyl)-acetamido]-acetic acid (15a, 0.38 g, 1.85 mmol) was dissolved in DMF (15 mL), and the solution was cooled down to −10° C., added with EDC (0.40 g, 2.03 mmol) for stirring 15 min, and then added with benzyl-2-(2-aminoacetamido)acetate, TFA salt (15b, 0.68 g, 1.85 mmol) and triethylamine (0.4 mL, 2.88 mmol). Finally, the reaction was replaced under room temperature with continuous stirring for 6 h. After the reaction was completed, DMF was removed by concentration under reduced pressure. The obtained solid was dissolved in ethyl acetate (50 mL), and then the organic phase was washed by H2O, 5% citric acid, H2O, saturated NaHCO3 and saturated NaCl solution separately, and dried over MgSO4 and concentrated under reduced pressure to remove ethyl acetate to obtain brown solid product. The product was purified by silica gel column chromatography, while the proportion of eluting solution is dichloromethane:methanol=1:0, 24:1, 19:1 in order, and yellow solid product 16 (0.33 g; 42.3%) is obtained. 1H-NMR (200 MHz) (DMSO) δ: 8.33 (t, 1H, Gly4-NH), 8.21 (t, 1H, Gly3-NH), 8.06 (t, 1H, Gly2-NH), 7.33-7.42 (m, 5H, ArH), 7.03 (t, 1H, Gly1-NH), 5.19 (s, 2H, CO2CH2Ph), 3.92 (d, 2H, Gly4-H), 3.76 (d, 4H, Gly3 and Gly2-H), 3.60 (d, 2H, Gly1-H), 1.40 [s, 9H, CO2C(CH3)3].

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