反应详情

To a mixed solution of tert-butyl (7-bromo-4,6-dimethyl-2,3-dihydro-1-benzofuran-5-yl)carbamate obtained in Example 222 (500 mg, 1.46 mmol) and cerous chloride (360 mg, 3.21 mmol) in THF (8 mL) was added dropwise at −78° C. under an argon atmosphere n-butyllithium (1.6 M hexane solution, 2.0 mL, 3.21 mmol). The mixture was stirred at the same temperature for 30 minutes, and then to the reaction solution was added dropwise a solution of 4-isopropylacetophenone (261 mg, 1.61 mmol) in THF (4 mL) and the resulting mixture was stirred for 30 minutes and elevated to room temperature. Water was added to the reaction solution and the product was extracted with ethyl acetate. The combined organic layers were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:hexane=2:3) to obtain 118 mg (yield: 19%) the title compound. Melting point: 185-186° C. (ethyl acetate-hexane).

1. stirringthe resulting mixture was stirred for 30 minutes
2. customelevated to room temperature
3. extractionthe product was extracted with ethyl acetate
4. washThe combined organic layers were washed with saturated brine
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography (ethyl acetate:hexane=2:3)