Cl.[CH:2]1([CH2:8][CH2:9][NH:10][CH2:11][CH2:12][C:13]([OH:15])=[O:14])[CH2:7][CH2:6][CH2:5][CH2:4][CH2:3]1.[C:16](=O)([O:22]C(C)(C)C)[O:17][C:18]([CH3:21])([CH3:20])[CH3:19].C(N(CC)CC)C.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>O1CCCC1>[C:18]([O:17][C:16]([N:10]([CH2:11][CH2:12][C:13]([OH:15])=[O:14])[CH2:9][CH2:8][CH:2]1[CH2:7][CH2:6][CH2:5][CH2:4][CH2:3]1)=[O:22])([CH3:21])([CH3:20])[CH3:19]Next, tetrahydrofuran (8 ml) was added to 3-[N-(2-cyclohexylethyl)amino]propionic acid hydrochloride (1.0 g, 4.2 mmol), and the mixture was stirred at room temperature. Di-t-butyl carbonate (1.1 g, 5.1 mmol) and triethylamine (1.3 ml, 9.3 mmol) were added to the mixture, the whole was stirred overnight, and then a 5% aqueous citric acid solution (10 ml) was added to the reaction mixture. The whole was extracted with chloroform (60 ml), and the obtained organic layer was washed with saturated brine (20 ml), dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to give 3-[N-(t-butoxycarbonyl)-N-(2-cyclohexylethyl)amino]propionic acid (0.79 g, 62%) as a colorless oily matter.
Loading…
