Friedel–Crafts acylation of benzene with acetyl chloride and AlCl3 yields which product?

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Multiple Choice

Friedel–Crafts acylation of benzene with acetyl chloride and AlCl3 yields which product?

In Friedel–Crafts acylation, the aromatic ring gets an acyl group attached by a Lewis acid–activated acyl chloride. Here, acetyl chloride reacts with AlCl3 to form the acylium ion CH3–CO+. This electrophile attacks the benzene ring, creating a σ-complex that loses a proton to restore aromaticity, yielding a benzene ring bearing a carbonyl group directly attached: acetophenone (1-phenylethanone), Ph–CO–CH3. This happens because the reaction delivers a ketone substituent, not a formyl group or a simple substitution without a carbonyl. The acyl group also deactivates the ring, typically preventing multiple substitutions.

In Friedel–Crafts acylation, the aromatic ring gets an acyl group attached by a Lewis acid–activated acyl chloride. Here, acetyl chloride reacts with AlCl3 to form the acylium ion CH3–CO+. This electrophile attacks the benzene ring, creating a σ-complex that loses a proton to restore aromaticity, yielding a benzene ring bearing a carbonyl group directly attached: acetophenone (1-phenylethanone), Ph–CO–CH3.

This happens because the reaction delivers a ketone substituent, not a formyl group or a simple substitution without a carbonyl. The acyl group also deactivates the ring, typically preventing multiple substitutions.

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