反应详情

D-Phenylalanine methyl ester (1.56 g of HCl salt, Aldrich in CH2Cl2 washed with saturated NaHCO3 and dried, 7.3 mmol) and diisopropylethylamine (2.1 ml, 8.9 mmol) in 1,2-dichloroethane (13 ml) was added dropwise over 30 min to a stirring solution of triphosgene (1.1 g, 5.2 mmol) in 1,2-dichloroethane (13 ml). After stirring at ambient temperature for 1.5 h, the reaction was cooled to 0° C. and aluminum chloride (2.2 g) was added. After refluxing for 2.5 h, the reaction was once again cooled to 0° C. and quenched by slowly adding water (13 ml). After stirring for 1 h, the reaction mixture was transferred to a separatory funnel with CH2Cl2. Extraction with CH2Cl2 (2×) and drying over MgSO4 afforded 1.8 g of crude product. Flash chromatography (SiO2, 0 to 100% EtOAc in CH2Cl2) afforded pure product (0.65 g, 43% yield). MS (ESI) 206 (M+H).

1. temperaturethe reaction was cooled to 0° C.
2. temperatureAfter refluxing for 2.5 h
3. temperaturethe reaction was once again cooled to 0° C.
4. customquenched by slowly adding water (13 ml)
5. stirringAfter stirring for 1 h
6. customthe reaction mixture was transferred to a separatory funnel with CH2Cl2
7. extractionExtraction with CH2Cl2 (2×)
8. dry with materialdrying over MgSO4
9. customafforded 1.8 g of crude product