反应详情

Isobutyryl chloride (10.4 mL, 98.04 mmol) was added drop wise to a stirred and a cooled (0° C.) solution of the product of Example 5E (61.28 mmol), diisopropylethyl amine (21.3 mL, 122.56 mmol), and 4-dimethylaminopyridine (0.30 g, 3.0 mmol) in dry dichloromethane (150 mL). The resulting solution was allowed to stir at 0° C. for five hours. After the completion of reaction (monitored by TLC), methanol (5 mL) was added to quench excess acid chloride. The solvent was removed under reduced pressure and the resulting slurry was partitioned using diethyl ether (200 mL) and saturated NH4Cl (100 mL). The organic layer was washed successively with 20% NaHSO4, NaHCO3, brine, and it was dried over MgSO4. After removal of solvent, the crude oil was purified over silica gel column using 10% diethyl ether in hexanes to give the title compound as a colorless oil: (20.5 g, 84% over 2 steps).

1. stirringto stir at 0° C. for five hours
2. additionwas added
3. customto quench excess acid chloride
4. customThe solvent was removed under reduced pressure
5. customthe resulting slurry was partitioned
6. washThe organic layer was washed successively with 20% NaHSO4, NaHCO3, brine, and it
7. dry with materialwas dried over MgSO4
8. customAfter removal of solvent
9. customthe crude oil was purified over silica gel column