反应详情

温度

60 °C

To 4.12 g (10.2 mmol) racemic (2R,3R and 2S,3S)-2-dibenzylamino-3-hydroxy-4-phenyl-butyric acid ethyl ester in 57 ml tetrahydrofurane were added 1.73 g (40.8 mmol) lithium hydroxide monohydrate dissolved in 10 ml water. The mixture was stirred at 60° C. overnight. Water was added followed by extraction with ethyl acetate. The waterphase was adjusted to pH 1 with 1 N aqueous hydrochloric acid. Extraction with ethylacetate and chromatography on silicagel with dichloromethane/methanol 9/1 yielded 3.40 g (89%) racemic (2R,3R and 2S,3S)-2-dibenzylamino-3-hydroxy-4-phenyl-butyric acid, MS m/e (%): 376.5 (M+H+, 100).

1. extractionfollowed by extraction with ethyl acetate
2. extractionExtraction with ethylacetate and chromatography on silicagel with dichloromethane/methanol 9/1