反应详情

To the solution of 8-4 (234.2 g, 0.784 mol) and concentrated HCl (720 mL) in ethanol (2.2 L) at room temperature, SnCl2.H2O (415 g, 2.0 mol) was added by portions. The mixture was stirred for 16 h. TLC showed the reaction was completed. The volatiles were removed in vacuo. The residue was quenched with cooled water (500 mL) and ethyl acetate (1.5 L). The aqueous layer was neutralized with KOH until PH=6˜7. The white precipitate was filtered off to get a clear solution, which was extracted with ethyl acetate (600 mL×3). The combined organic layers were washed with brine twice, dried over anhydrous sodium sulfate. After filtration and evaporation, 8-5 (212.7 g, 100%) was obtained as brownish white solid.

1. customThe volatiles were removed in vacuo
2. customThe residue was quenched with cooled water (500 mL) and ethyl acetate (1.5 L)
3. filtrationThe white precipitate was filtered off
4. customto get a clear solution, which
5. extractionwas extracted with ethyl acetate (600 mL×3)
6. washThe combined organic layers were washed with brine twice
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationAfter filtration and evaporation