Friedel Crafts alkylation
Friedel-Crafts alkylation attaches an alkyl group to benzene.
- Reagents
- haloalkane and anhydrous AlCl3
- Conditions
- anhydrous conditions
- Reaction class
- electrophilic substitution
- Equation
- C6H6 + RCl -> C6H5R + HCl
Overview
Friedel-Crafts alkylation attaches an alkyl group to benzene.
Transformation
- Equation
- C6H6 + RCl -> C6H5R + HCl
- Reagents
- haloalkane and anhydrous AlCl3
- Environment
- anhydrous conditions
- Reaction class
- electrophilic substitution
- Mechanism
- Friedel-Crafts alkylation
- Evidence level
- textbook core
Scope and limitations
- Scope
- Benzene reacts with a haloalkane in the presence of aluminium chloride to form an alkylarene.
- Limitations
- Carbocation rearrangement and multiple alkylation can occur; strongly deactivated rings do not react readily.
Related reactions
- Combustion: Benzene → Carbon dioxide
Benzene combusts to carbon dioxide and water and tends to burn with a smoky flame.
- Bromination: Benzene → Halogenoarenes
Benzene undergoes bromination with a halogen carrier catalyst to form bromobenzene.
- Nitration: Benzene → Nitroarenes
Benzene is nitrated by concentrated nitric and sulfuric acids to form nitrobenzene.
- Friedel Crafts acylation: Benzene → Acylbenzenes
Friedel-Crafts acylation attaches an acyl group to benzene.
- Ring hydrogenation: Benzene → Cyclohexane
Benzene gives cyclohexane through ring hydrogenation.
- Nitration: Benzene → Nitrobenzene
Benzene gives nitrobenzene through nitration.
References
- Organic Chemistry: Alkylation and Acylation of Aromatic Rings: The Friedel–Crafts ReactionJohn McMurry · OpenStax Organic Chemistry · 2023
Supports AlCl3-assisted formation of alkyl and acylium electrophiles, aromatic sigma-complex formation and deprotonation; also records carbocation rearrangement and polyalkylation boundaries for Friedel–Crafts alkylation.