Rare-Earth Solid Super Acid Catalyst For Friedel-Crafts Acylation Of Ferrocene

Friedel-Crafts acylation is the basic way to synthesize acylferrocene. The conventional catalysts are Lewis acid (AlCl₃,FeCl₃,TiCl₄,BF₃ ,etc) and proton acid (HF,H₂SO₄,HCl), but these catalysts have many disadvantages, such as bad selectivity, more side reaction, low yield, strong corrosion,difficulty in separation and recovery, serious environment pollution etc. Considerable efforts are being made to find recyclable and environment-friendly catalysts for Friedel-Crafts type acylation reactions. We prepared several kinds of solid acids—SO₄^2-/ZrO₂ and bentonite supported rare earth acids, and singled two out signed YbN and BLa as the best for Friedel-Crafts acyaltion of ferrocene. The optimum reaction conditions were also explored. YbN and BLa were characterized by IR spectra, XRD, TDA-TG, specific surface area and SEM.It indicated that two catalysts mentioned above had fair high catalytic activity when they were used into Friedel-Crafts acylation .Taken the reaction of ferrocene with heptanoyl chloride as reactants, the influential factors of reaction were investigated. 0.5g ferrocene and 30ml ethylene chloride were heated at 100℃ . When catalyst YbN was used, the appropriate conditions were as follows: catalyst 0.2g , n(ferrocene) : n(acylating agent)= 1 : 2, raction time 5h, the yield of heptanoyl ferrocene was about 75.5%; the best conditions using catalyst BLa were as follows: catalyst 0.2g, n(ferrocene) : n(acylating agent)= 1 : 2, raction time 4h, the yield of heptanoyl ferrocene was about 71.0%.