# Why is meta xylene formed when toluene undergoes alkylation in presence of excess AlCl3?

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.

• The o and p xylenes formed rearrange to more stable m-xyle in presence of $\ce{AlCl3}$ Oct 8 '21 at 11:34
• Oct 8 '21 at 11:43
• meta xylene is more thermodynamically stable, so if you heat enough then you will get meta as your major product. Oct 8 '21 at 12:34
• 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?
– PCK
Oct 8 '21 at 12:49
• Oct 8 '21 at 14:41