Water → Z-Glu(Nle-OBzl)-OBzl

Participants

Reaction Conditions

Reaction Steps

The resulting H-Nle-OBzl.HCl was dissolved in methylene chloride (30 mL) and the resulting reaction solution was maintained at 0° C. To the reaction solution, Z-Glu-OBzl (N-α-carbobenzoxy-L-glutamic acid α-benzyl ester, 0.70 g, 1.90 mM), triethylamine (0.29 mL, 1.1 eq., 2.10 mM), HOBt.H2O (1-hydroxybenzotriazole hydrate, 0.32 g, 1.1 eq., 2.10 mM), and WSC.HCl (0.41 g, 1.1 eq., 2.10 mM) was added. The temperature of the reaction solution was gradually raised and stirred at room temperature overnight (16 hours). Then, the reaction mixture was concentrated under reduced pressure, ethyl acetate (100 mL) was added to the resulting residue, and the organic phase was then washed once with water (30 mL), twice with a 5% aqueous solution of citric acid (30 mL), once with a saturated common salt solution (30 mL), twice with a 5% aqueous solution of sodium hydrogen carbonate (30 mL) and once with a saturated common salt solution (30 mL). Then, the organic phase was dried over anhydrous magnesium sulfate. The magnesium sulfate was removed through filtration and the filtrate was concentrated under reduced pressure. The resulting residue was recrystallized from ethyl acetate and n-hexane, the crystals thus obtained were collected through filtration and dried under reduced pressure to give crystals of Z-Glu(Nle-OBzl)-OBzl (0.91 g).

Provenance & Evidence