I guess this reaction is a nucleophilic aromatic substitution where $\ce{ONa-}$ is the nucleophile $\ce{Cl-}$ the leaving group, is that right?

enter image description here

Methyl group is a ortho-, para- director. So why should I have a meta product here? Don't we need an electron withdrawing group ($\ce{NO2}$ , carbonyl) in a NAS-reaction which is at ortho or para positions to the leaving group?

I am a bit confused about the shown picture.

  • $\begingroup$ Could be because of ipso substitution. This link might help. $\endgroup$ Feb 14, 2018 at 15:18
  • $\begingroup$ thank you for the link. the ipso subst leaving group seems to be at ortho or para positions as ı mentioned. but in the reaction ı provided it is at meta. that is what is confusing me $\endgroup$
    – Taylan
    Feb 14, 2018 at 15:24

1 Answer 1


What is going on here is a benzyne process. Under the conditions of intense heat the hydroxide removes one of the protons either side of the Cl. Cl- then leaves to create a triple bond, giving a benzyne. As you might imagine this is a highly reactive species and reacts with the OH- with no regioselectivity; either end can get hydroxylated and you have two possible benzyne intermediates. Thus you get the mixture of products.


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