反应详情

A solution of the compound (9.14 g, 17.2 mmol) obtained in Example 60-5) in 2 N hydrochloric acid-1,4-dioxane (200 mL) was stirred at 50° C. for 2 h. The reaction mixture was cooled to room temperature, methanol (40 mL) was added to the reaction mixture, and insoluble substances were dissolved by sonication. Saturated aqueous sodium hydrogencarbonate (400 mL) was added to the reaction mixture, and the mixture was extracted with dichloromethane and purified by silica gel column chromatography (ethyl acetate:methanol=3:2) to obtain the title compound (2.74 g, 38%) as a white solid.

1. dissolutionwere dissolved by sonication
2. extractionthe mixture was extracted with dichloromethane
3. custompurified by silica gel column chromatography (ethyl acetate:methanol=3:2)