反应详情

To a 3 ml tetrahydrofuran solution of 150 mg (0.36 mmol) of the compound obtained in Example 15, 0.45 ml of n-butyl lithium (1.59M hexane solution 0.72 mmol) was added dropwise at −78° C. After the mixture was stirred at the same temperature for 30 minutes, 33.4 μl (0.43 mmol) of N,N-dimethylformamide was added dropwise to the reaction mixture, followed by stirring the mixture at −78° C. for 2 hours. Then, an aqueous solution of ammonium chloride was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate, whereafter the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=2/1) to obtain 73 mg (55%) of the captioned compound.

1. stirringby stirring the mixture at −78° C. for 2 hours
2. extractionthe mixture was extracted with ethyl acetate
3. washThe organic layer was washed with water
4. dry with materiala saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate, whereafter the solvent
5. distillationwas distilled off under reduced pressure
6. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate=2/1)