反应详情

A 5 liter, 3-neck round bottom flask equipped with a water condenser, heating mantle and overhead stirrer was charged with glacial acetic acid (0.75 L) and 200 proof ethanol (0.75 L) followed by addition of the product from Example 17C (40.0 g, 60 mmol) and iron powder (13.3 g, 240 mmol). The mixture was then heated to reflux for 6 hours, cooled to ambient temperature and diluted with 1.0-1.5 L of EtOAc, stirred for 10-15 minutes and diluted with 1.0 L of water. The two-phase mix was stirred vigorously for 5-10 minutes and the layers were allowed to separate. The red aqueous layer was removed and discarded. The remaining EtOAc layer with suspended solids was washed 6×1.0 L with water eventually removing all of the red color. The EtOAc layer was then filtered to collect a cream colored solid which was rinsed with 300 mL EtOAc and dried to constant mass in a vacuum oven (40° C., house vacuum, 24 hours) to give of the title compound (37 g, 97%).

1. customA 5 liter, 3-neck round bottom flask equipped with a water condenser
2. temperatureheating mantle and overhead stirrer
3. temperatureThe mixture was then heated
4. temperatureto reflux for 6 hours
5. additionThe two-phase mix
6. stirringwas stirred vigorously for 5-10 minutes
7. customto separate
8. customThe red aqueous layer was removed
9. washwas washed 6×1.0 L with water
10. customeventually removing all of the red color
11. filtrationThe EtOAc layer was then filtered
12. customto collect a cream colored solid which
13. washwas rinsed with 300 mL EtOAc
14. customdried to constant mass in a vacuum oven (40° C., house vacuum, 24 hours)