Friedel-Crafts Reaction


Also found in: Wikipedia.

Friedel-Crafts reaction

[frē¦del ′krafs rē‚ak·shən]
(organic chemistry)
A substitution reaction, catalyzed by aluminum chloride in which an alkyl (R‒) or an acyl (RCO‒) group replaces a hydrogen atom of an aromatic nucleus to produce hydrocarbon or a ketone.

Friedel-Crafts Reaction

 

a method of alkylating and acylating aromatic compounds in the presence of acidic catalysts, such as AlCl3, BF3, ZnCl2, FeCl3, mineral acids, oxides, and cation-exchange resins. The alkylating agents used are alkyl ha-lides, olefins, alcohols, and esters. The acylating agents include carboxylic acids and their acid halides and their anhydrides.

The Friedel-Crafts reaction is a typical electrophilic substitution reaction in the aromatic nucleus; the role of the catalyst amounts to the generation of an attacking particle—an alkyl or acyl cation.

Examples are given below of the interaction of benzene with the ethyl chloride and the acid chloride of acetic acid:

Friedel-Crafts alkylation is used in industry to produce high-octane fuels, antioxidants, surfactants, perfumes, ethylbenzene (starting material in styrene manufacture), and other important products, such as cumene and thymol. Friedel-Crafts acylation is a basic method of synthesizing aromatic and aliphatic-aromatic ketones, many of which are intermediate products in the manufacture of pharmaceuticals and various dyes, such as Michler’s ketone.

The Friedel-Crafts reaction was discovered by C. Friedel and J. Crafts in 1877–78.

References in periodicals archive ?
The mechanistic pathway for this process involves the N-O bond cleavage of TEMPO-substituted 1,3-dicarbonyl compounds to form the tricarbonyl intermediate, following Friedel-Crafts reaction of indole/aza-indole/pyrrole with this intermediate generates the tertiary alcohol product.
The Friedel-Crafts reaction of arene with activated ketone is an important method for the preparation of tertiary alcohol.
Re-cently, our group reported the synthesis of indole substituted tertiary alcohols through the Friedel-Crafts reaction of indoles with vicinal tricarbonyl compounds generated in situ from 1,3-dicarbonyl compounds and TEMPO [23].
76 ppm belong to carbon (d) in methylene linker formed after Friedel-Crafts reaction and methylene of polymer backbone [25], The broad peak at around 130 ppm is assigned to the carbon (f) of imidazole ring and overlapping with peaks due to phenyl carbon [13], The chemical composition and content of various elements of HCPs incorporated with imidazolium salts were further confirmed by Elemental Analyses (EA) (shown in Table 1).
The Friedel-Crafts reaction is carried out with methylene chloride as the solvent.
112) Role of the Friedel-Crafts reaction in recycled SBR/thermoplastics blending.
Chemical synthesis using ordinary light to replace the Friedel-Crafts reaction and associated hazards.
In his work to replace the Friedel-Crafts reaction - which involves an acid chloride or anhydride and a benzene-type compound in the presence of a Lewis acid - Kraus has focused on the synthesis of benzodiazepines, which include the drug Valium.
He was sitting in his office reading about something called the Friedel-Crafts reaction, which can be used to produce solvents and detergents.
Two kinds of benzophenone (BP) derivatives, dodecyl-benzophenone (BP-D) and hexadecoxyl-benzophenone (BP-H), used as new photoinitiators have been synthesized by Friedel-Crafts reactions and identified by ultraviolet (UV) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis.
In the present work, we have prepared the two BP derivatives dodecyl-benzophenone (BP-D) and hexadecoxyl-benzophenone (BP-H) with a long carbochain by Friedel-Crafts reactions and identified by UV spectroscopy, IR spectroscopy, and elemental analysis.
The Friedel-Crafts reactions can be presented as the following general formula: