反应详情

温度

25 °C

D-Homophenylalanine Benzyl ester Tosylate (2.48 g, 5.6 mmol) was suspended in ethyl acetate (25 mL) and a saturated solution of sodium bicarbonate in water was added in portions (25 mL) with stirring at 25° C. The water layer was extracted with ethyl acetate (3×10 mL). The combined organic extract was dried over anhydrous sodium sulfate, filtered and concentrated to dryness to afford D-Homophenylalanine Benzyl ester. The ester was dissolved in acetonitile (25 mL). NaNd-bis-Boc-L-Ornithine (2.0 g, 6.0 mmol) was then added followed by N-hydroxysuccinimide (50 mg) and dicyclohexylcarbodiimide (1.28 g, 6.2 mmol). The reaction was stirred at 25° C. for 30 hr, filtered and the filtrate concentrated to dryness to afford crude product. It was purified by column chromatography on silica gel (hexane:ethyl acetate=3:1), which gave the title product (2.80 g) as white solid.

1. filtrationfiltered
2. concentrationthe filtrate concentrated to dryness
3. customto afford crude product
4. customIt was purified by column chromatography on silica gel (hexane:ethyl acetate=3:1), which