Question

Write a note on Friedel Craft reaction.

Answer 1

Friedel-Crafts reaction is the reaction which adds alkyl or acyl group to a benzene ring, using a Lewis acid like FeCl3 or AlCl3.

Benzene ring attack the slightly-positive carbon, which would attract such electron-rich factors like benzene ring, hence this type of reaction electrophilic reaction.

Since the carbon is full with 4 bonds already, something would have to leave. That’s where iron (III) chloride takes place: it removes chloride from the alkyl chloride.

Answer 2

Friedel Craft reaction

• The reactions where alkyl or acyl groups are attached to benzene or aromatic rings are called Friedel Craft reactions.
• Generally, two main Friedel Craft reactions are-

1. Friedel Craft alkylation
2. Friedel Craft Acylation

• This reaction takes place through the electrophilic aromatic substitution mechanisms.
• Anhydrous aluminium trichloride or ferric chloride is used as a catalyst in these reactions.