Search results
Results From The WOW.Com Content Network
The Friedel–Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877 to attach substituents to an aromatic ring. [1] Friedel–Crafts reactions are of two main types: alkylation reactions and acylation reactions. Both proceed by electrophilic aromatic substitution. [2] [3] [4] [5]
This reaction is typically catalyzed by the corresponding iron or aluminum trihalide. The Friedel–Crafts reaction can be performed either as an acylation or as an alkylation. Often, aluminium trichloride is used, but almost any strong Lewis acid can be applied. For the acylation reaction a stoichiometric amount of aluminum trichloride is ...
Friedel-Crafts alkylation of benzene is often catalyzed by aluminium trichloride. Electrophilic alkylation uses Lewis acids and Brønsted acids, sometimes both. Classically, Lewis acids, e.g., aluminium trichloride, are employed when the alkyl halide are used. Brønsted acids are used when alkylating with olefins.
The Friedel-Crafts alkylation process involves chlorination of n-paraffins to monochloroparaffins followed by alkylation of benzene using aluminum chloride (AlCl 3) catalyst. This method is one of the oldest commercial routes to LABs. Each process generates LAB products with distinct features.
Cumene is formed in the gas-phase Friedel–Crafts alkylation of benzene by propene. Benzene and propene are compressed together to a pressure of 30 standard atmospheres at 250 °C in presence of a catalytic Lewis acid. Phosphoric acid is often favored over aluminium halides.
Friedel-Crafts alkylation: alkylbenzenes can be synthesized from olefins or alkyl halides with aromatic compounds in the presence of a catalyst such as AlCl 3, HF, or H 2 SO 4. [ 4 ] Gattermann-Koch reaction : named after German chemists Ludwig Gattermann and Julius Arnold Koch , the Gattermann-Koch reaction is a catalyzed formylation of ...
In electrophilic substitution in aromatic compounds, an atom appended to the aromatic ring, usually hydrogen, is replaced by an electrophile.The most important reactions of this type that take place are aromatic nitration, aromatic halogenation, aromatic sulfonation and acylation and alkylating Friedel-Crafts reactions.
Clemmensen reduction conditions are particularly effective at reducing aryl [4]-alkyl ketones, [5] [6] such as those formed in a Friedel-Crafts acylation. The two-step sequence of Friedel-Crafts acylation followed by Clemmensen reduction constitutes a classical strategy for the primary alkylation of arenes.