反应详情

To a solution of 900 mg (S)-4-benzyloxy-2-tert-butoxycarbonylamino-butyric acid in 10 ml DMF were added 1.5 ml N-ethylmorpholine, 0.43 ml 1-ethoxycarbonylpiperazine and 955 mg TOTU. The solution was stirred for 12 h before being diluted with ethyl acetate and extracted subsequently with aqueous LiCl (4%), 0.1 M HCl and saturated NaHCO3. The crude product obtained after evaporation of the solvent was used without further purification. Yield: 1.23 g.

1. extractionextracted subsequently with aqueous LiCl (4%), 0.1 M HCl and saturated NaHCO3