Hydrochloric Acid → HCID 178440842, compound

Participants

Reaction Steps

First, a nitrogen purged flask was charged with 350 ml of dichloroethane, 50.0 g (122 mmol) of tetra-tert-butylferrocene (prepared according to T. Leigh, J. Am. Chem. Soc. 1964, 3294-3302), and 19.3 ml (126 mmol) of 6-bromohexanoyl chloride. Second, the solution was cooled to 0 degrees centigrade, whereupon 13.3 g (100 mmol) of AlCl3 was charged into th e reaction vessel in 3 equal portions at two hour intervals. It will be understood that the freshness and/or purity of the AlCl3 can impact the degree of substitution of, for example, tert-butyl groups on a cyclopentadienyl ligand. Third, the reaction mixture was then slowly poured into 300 ml of agitating H2O. Fourth, the organic-aqueous mixture was charged with a sufficient quantity of diethyl ether so that an organic layer was appreciably formed on top of the aqueous layer. Fifth, 50 ml of concentrated hydrochloric acid (HCl) was charged into the vessel. Sixth, approximately 2-5 g of zinc dust was charged into the vessel to reduce any ferrocinium species present in the aqueous layer to the ether soluble ferrocene. Once the layers were clearly defined, they were separated and the aqueous layer was extracted with 200 ml of diethyl ether (Et2O). The two organic portions were combined and washed with NaHCO3 and brine. Next the organic solution was dried over MgSO4. The organic solution was then decanted from the MgSO4 and filtered. Next, the solvent was removed by rotary evaporation to yield a red oil. The red oil was applied to a vacuum assisted silica gel column and washed with hexane to remove any residual ferrocene. The product was eluted with Et2O. Upon solvent removal and cooling in a freezer, 64.29 g of 6-bromo-1-(tetra-tert-butylferrocenyl)-2-hexanone was isolated as a red solid.

Provenance & Evidence