反应详情

A solution of the product from Example 9 (1.05 g, 4.28 mmol) and triethylamine (0.44 g, 4.35 mmol) in 10 mL of CH2Cl2 was cooled to 0° C. and ethyl chloroformate (0.47 g, 4.33 mmol) in 5 mL CH2Cl2 was added dropwise. The reaction was warmed to room temperature and washed with water. The aqueous phase was extracted with CH2Cl2 (3×20 mL) and the combined organic extracts were dried (MgSO4), filtered and concentrated. The residue was purified by chromatography (silica gel, 1:1 heptane/ethyl acetate) to give the title compound (1.33 g, 98%) as an oil.

1. washwashed with water
2. extractionThe aqueous phase was extracted with CH2Cl2 (3×20 mL)
3. dry with materialthe combined organic extracts were dried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by chromatography (silica gel, 1:1 heptane/ethyl acetate)