Reaction of Benzene with Propene

Friedel-Crafts reaction of benzene with propene in the presence of AlCl3 gives Isopropylbenene or Cumene
Chemistry Question Answer
Chemistry Question Answer

Friedel-Crafts reaction of benzene with propene in the presence of AlCl3 gives
A. n-Propyl benene
B. 4-Ethyltaulene
C. Isopropylbenene
D. 2-Ethyltoluene

[KSET 2013]

Friedel-Crafts reaction of benzene with propene in the presence of AlCl3−HCl as the catalyst at 110°C under high pressure exhibited the highest selectivity for cumene of 99%.
reaction of benene with propene | KSET 2013
When the propene reacts with the HCl, there are two different ways that the initial stage of the addition reaction could happen.
Reaction of propene with HCl
The secondary carbocation (carbonium ion) is the more stable and forms more readily. Due to more stable carbocation, it is the electrophile that will be attach to the benzene ring and forms cumene (isopropylbenzene).
The chloride ion is immediately picked up by the aluminium chloride to form an AlCl4- ion. That prevents the chloride ion from reacting with the carbocation to form chloropropane.
AlCl4

Itroduction of electrophile to benzene ring-
Reaction of Benzene with Propene

Correct answer is option C. Isopropylbenene also called Cumene

Friedel-Craft Alkylation Reaction Involving Rearrangement
Try to draw the mechanism of this reaction

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