反应详情

A stirred suspension of 5-[(4-methoxyphenyl)sulfonyl]-6-methyl-5,6-dihydrophenanthridine (0.73 g, 2.0 mmol) was heated to 50° C. in glacial acetic acid 20 mL) and treated drop-wise over seven hours with excess bromine (1.92 g, 12 mmol). After cooling to room temperature, the reaction mixture was diluted with ethyl acetate and the precipitate filtered. The organic phase filtrate was washed sequentially with a saturated, aqueous sodium thiosulfate solution, a 1 N hydrochloric acid solution, and water. The organic phase was further washed sequentially with a 2.5 N aqueous sodium hydroxide solution until a basic extract was obtained, water, and a saturated aqueous sodium chloride solution. The organic phase was dried over anhydrous sodium sulfate, filtered through a short column of silica gel, and the solvent removed in vacuo to afford a crude yellow solid (0.75 g, 1.7 mmol, 85%). The crude solid was purified by preparative chromatography on a Biotage® 40 Mi column of pre-packed silica gel (90 g), eluting with a mixture of methyl tert-butyl ether-hexane (15:85) at a flow rate of 40 mL/min to afford, after evaporation of the solvent, a solid. Crystallization of the solid from a mixture of diethyl ether-hexane yielded the title compound (0.43 g, 0.97 mmol, 48%) as a homogeneous, colorless, crystalline solid, m.p. 192-194° C.;

1. filtrationthe precipitate filtered
2. washThe organic phase filtrate was washed sequentially with a saturated, aqueous sodium thiosulfate solution
3. washThe organic phase was further washed sequentially with a 2.5 N aqueous sodium hydroxide solution until
4. extractiona basic extract
5. customwas obtained
6. dry with materialThe organic phase was dried over anhydrous sodium sulfate
7. filtrationfiltered through a short column of silica gel
8. customthe solvent removed in vacuo
9. customto afford a crude yellow solid (0.75 g, 1.7 mmol, 85%)
10. customThe crude solid was purified by preparative chromatography on a Biotage® 40 Mi column of pre-packed silica gel (90 g)
11. washeluting with a mixture of methyl tert-butyl ether-hexane (15:85) at a flow rate of 40 mL/min
12. customto afford
13. customafter evaporation of the solvent
14. customCrystallization of the solid
15. additionfrom a mixture of diethyl ether-hexane