反应详情

25.00 g (204.6 mmol) of 1,2,4,5-tetramethyl-cyclopenta-1,3-diene (HMe4Cp) was charged into a reaction vessel and dissolved in approximately 200 ml of hexane while under positive nitrogen pressure. The solution was cooled with an ice bath to approximately 0° C., whereupon 84 ml (210 mmol) of 2.5M n-butyllithium was charged into the reaction vessel via syringe. Next, the reaction mixture was allowed to warm to room temperature while being agitated overnight. In a separate vessel, 1.95 g (35 mmol) of Fe in approximately 100 ml of tetrahydrofuran (THF) was purged with nitrogen and then cooled to 0° C. 11.56 g (70 mmol) of FeCl3 was charged into the Fe/THF mixture in 3 equal portions, whereupon the mixture was heated to reflux for approximately 2 hours under a nitrogen atmosphere. The FeCl2-2THF was then cooled to room temperature, and transferred to the LiMe4Cp suspension via cannula. The complete mixture was heated to reflux for 2 hours. After cooling, the reaction was quenched by the addition of approximately 300 ml of water and a small amount of zinc powder. The reaction mixture was charged into a separatory funnel, whereby the organic layer was isolated and collected. The aqueous layer was extracted with Et2O. Next, the organic layers were combined, washed with a saturated brine solution, dried over MgSO4, and filtered. The solvents were then removed by rotary evaporation to give an orange solid which was washed with MeOH and collected on a vacuum frit. Additional product was recovered by reducing the volume of the MeOH solution and cooling in a freezer overnight. The total yield was approximately 22 g of octamethylferrocene.

1. additionwas charged into the reaction vessel via syringe
2. temperaturecooled to 0° C
3. temperaturewas heated
4. temperatureto reflux for approximately 2 hours under a nitrogen atmosphere
5. temperatureThe complete mixture was heated
6. temperatureto reflux for 2 hours
7. temperatureAfter cooling
8. customthe reaction was quenched by the addition of approximately 300 ml of water
9. additionThe reaction mixture was charged into a separatory funnel
10. customwhereby the organic layer was isolated
11. customcollected
12. extractionThe aqueous layer was extracted with Et2O
13. washwashed with a saturated brine solution
14. dry with materialdried over MgSO4
15. filtrationfiltered
16. customThe solvents were then removed by rotary evaporation
17. customto give an orange solid which
18. washwas washed with MeOH
19. customcollected on a vacuum frit
20. customAdditional product was recovered
21. temperaturecooling in a freezer overnight