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My book says that in presence of excess aluminium chloride, when toluene reacts with methyl iodide, meta-xylene is the major product. Why aren't ortho-para products favored here?

Edit: The book is "Higher Secondary Chemistry Second Paper", third edition (reprint: 2013) by Haradhan Nag. The reaction is given on page 292.

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    $\begingroup$ The o and p xylenes formed rearrange to more stable m-xyle in presence of $\ce{AlCl3}$ $\endgroup$
    – Jayadithya
    Oct 8 at 11:34
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    $\begingroup$ See this: pubs.acs.org/doi/pdf/10.1021/ja01626a038 $\endgroup$
    – Jayadithya
    Oct 8 at 11:43
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    $\begingroup$ meta xylene is more thermodynamically stable, so if you heat enough then you will get meta as your major product. $\endgroup$ Oct 8 at 12:34
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    $\begingroup$ Huh, that's cool. TIL. The HC Brown paper above pre-dates the Woodward-Hoffmann rules, but presumably the rearrangement is via a suprafacial (thermally allowed) pericyclic 1,5-carbon shift in the intermediate cation? $\endgroup$
    – PCK
    Oct 8 at 12:49
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    $\begingroup$ Related: Thermodynamic stability of meta-xylene over ortho- and para-isomers $\endgroup$
    – orthocresol
    Oct 8 at 14:41
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Alkylation seems to be reversible under duress. To make a decent analysis product ratios and times would be informative. The initial formation of ortho and para is because of lower activation energies. If they can equilibrate meta is favored over ortho because of steric effects and over para because there are twice as many meta and the electronic effect that stabilizes the transition state should actually raise the energy of the para ground state. Subtle perhaps but it does not take much energy difference to change close product ratios.

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