反应详情

N-Methylmorpholine (0.87 ml, 7.9 mmol), 1-hydroxybenzotriazole (0.46 g, 3.41 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.65 g, 3.41 mmol) were added in this sequence to a solution of commercially available (R)-6-benzyloxycarbonylamino-2-tert-butoxycarbonylamino-hexanoic acid (1 g, 2.63 mmol) and commercially available (S)-2-amino-3-methylbutyramide hydrochloride (0.40 g, 2.63 mmol) in 12 ml of CH2Cl2 and 4 ml of DMF, and the mixture was stirred at RT for about 14 h. Flash chromatography (gradient heptane/AcOEt to CH2Cl2/MeOH) afforded 1 g of the product (79%).