反应详情

温度

70 °C

To a solution of (1-carbamoyl-cyclopropyl)-carbamic acid benzyl ester (3.0 g, 8.1 mmol) in THF (100 mL) was added NaHCO3 (9.7 g, 120 mmol) and 3-bromo-2-oxo-propionic acid ethyl ester (8.1 mL, 64.0 mmol). The reaction was heated at 70° C. for 15 h. The resulting orange suspension was filtered through celite and concentrated under reduced pressure. The resulting orange oil was dissolved in THF (10 mL) and to this was added trifluoroacetic anhydride (1 mL). The mixture was stirred at room temperature for 24 h. The reaction was quenched with satd NaHCO3 and extracted with EtOAc (3×50 mL). The combined extracts were washed with water, brine and dried with MgSO4. The mixture was filtered, concentrated and purified by reverse phase HPLC. The combined HPLC fractions were extracted with EtOAc (3×100 mL). The extracts were washed with water, brine and dried with MgSO4. The mixture was filtered and concentrated to give 2-(1-benzyloxycarbonylamino-cyclopropyl)-oxazole-4-carboxylic acid ethyl ester (1.3 g, 3.9 mmol) as a white solid.

1. filtrationThe resulting orange suspension was filtered through celite and
2. concentrationconcentrated under reduced pressure
3. dissolutionThe resulting orange oil was dissolved in THF (10 mL)
4. additionto this was added trifluoroacetic anhydride (1 mL)
5. customThe reaction was quenched with satd NaHCO3
6. extractionextracted with EtOAc (3×50 mL)
7. washThe combined extracts were washed with water, brine
8. dry with materialdried with MgSO4
9. filtrationThe mixture was filtered
10. concentrationconcentrated
11. custompurified by reverse phase HPLC
12. extractionThe combined HPLC fractions were extracted with EtOAc (3×100 mL)
13. washThe extracts were washed with water, brine
14. dry with materialdried with MgSO4
15. filtrationThe mixture was filtered
16. concentrationconcentrated