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Homework Help: Chemistry: Not a Friedel-Crafts Reaction

  1. Sep 14, 2010 #1
    1. The problem statement, all variables and given/known data

    (a) Draw the product that would be formed.
    (b) Provide a brief explanation for this and provide a couple of sentences and key mechanistic step(s) to illustrate your reasoning


    24zliye.png

    3. The attempt at a solution

    Here is my reasoning and what I believe the reaction would turn out to be if Benzene was reacted with C5H11Cl:

    Alkyl halides, among other molecules such as alkenes and alcohols would not form according to Friedel-Crafts' reaction because there are more stable molecules or carbocations. C5H11Cl would change to tert-Butylbenzene (below) because the intermediate of the product would create a 3° structure first from the non-Cl side.

    http://commons.wikimedia.org/wiki/File:Tert-Butylbenzene.svg" [Broken]

    Does this seem reasonable? I know that the 3° is the most stable of the carbocations, but I do not know if this is correct reasoning for the reaction. Does the Cl perhaps remain attached also?
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Sep 15, 2010 #2
    I re-looked at it, and noticed that there would be a carbon missing if the answer was what I put.

    I would change my answer so that the middle Carbon furthest from benzene would have another carbon.

    Does this seem more reasonable?
     
  4. Sep 18, 2010 #3
    You're on the right track. Friedel-Crafts alkylation involves a carbocation intermediate. As with all carbocations, this intermediate will rearrange itself.

    This wouldn't form a t-butyl carbocation, by the way, it would form a neopentyl carbocation. One way that this group can rearrange is through a methyl shift, which would put the positive charge on a tertiary center.
     
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