反应详情

The compound obtained in Example 65 (4.89 g, 7.85 mmol) was dissolved in acetic acid (5 ml). To the solution was added 30% solution of hydrogen bromide in acetic acid (15 ml), and the mixture was stirred at room temperature for 30 minutes. To the reaction mixture was added diethylether (60 ml), and supernatant solution was removed by decantation. To the residure was added diethylether (60 ml), and supernatant solution was removed by decantation. These procedure was repeated further three times. To the residue was added aqueous solution of 1N-sodium hydroxide (50 ml) and the mixture was extracted with dichloromethane (80 ml, 30 ml×2). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The concentrate was subjected to column chromatography (alumina 200 g, ethyl acetate/methanol=1/0 to 4/1 to 1/1), and the desired fraction was concentrated under reduced pressure to give the titled compound (3.18 g, 6.51 mmol, Yield 83%) as pale brown oily substance.

1. customwas removed by decantation
2. additionTo the residure was added diethylether (60 ml), and supernatant solution
3. customwas removed by decantation
4. additionTo the residue was added aqueous solution of 1N-sodium hydroxide (50 ml)
5. extractionthe mixture was extracted with dichloromethane (80 ml, 30 ml×2)
6. dry with materialThe organic layer was dried over anhydrous sodium sulfate
7. concentrationconcentrated under reduced pressure
8. concentrationthe desired fraction was concentrated under reduced pressure