反应详情

A solution of dicyclohexylcarbodiimide (DCC, 8.3 g, 40 mmol) in acetone (100 ml) was added dropwise a suspension of Boc-asparagine (9.3 g, 40 mmol) in pyridine (50 mL) at 0° C. under nitrogen. The reaction mixture was stirred at ambient temperature for 3 h. The mixture was filtered and the filtrate was concentrated. The residue was dissolved in dichloromethane (400 mL) and the solution was washed with 2 N aqueous HCl (20 mL×3) and brine (200 mL), dried over anhydrous sodium sulfate, and concentrated to afford (S)-2-(tert-butoxycarbonylamino)-3-cyanopropanoic acid (5.5 g, 56% yield), which was used directly without further purification.

1. filtrationThe mixture was filtered
2. concentrationthe filtrate was concentrated
3. dissolutionThe residue was dissolved in dichloromethane (400 mL)
4. washthe solution was washed with 2 N aqueous HCl (20 mL×3) and brine (200 mL)
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated