In Dow's process of manufacture of phenol, $\ce{PhCl}$ is fused with $\ce{NaOH}$ at high temperature and pressure. What are the possible side products? And what is the intermediate formed?

I think the intermediate will be benzyne. After the formation of benzyne, $\ce{OH-}$ nucleophilic attack takes place. the reaction mixture also contains some phenoxide ions. So Diphenyl ether is a possible side product (Formed by nucleophilic attack of $\ce{PhO-}$). But the answer given species two side products: Diphenyl ether and p-phenyl phenol. How can I explain the second product?

  • $\begingroup$ $\ce{C6H5ONa}$ might again react with left over $\ce{C6H5Cl + NaOH}$ $\endgroup$ Mar 5, 2016 at 11:19

1 Answer 1


Before we can consider the reaction, we must consider the conversion of the reactants into the reacting species:

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Now, we may consider the reaction occurring between these two species:

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The product of this reaction is now easily converted into para-phenyl phenol by an acid workup.

  • $\begingroup$ The benzyne should be write between square brakets because it is not an isolated compound. $\endgroup$
    – ParaH2
    Mar 5, 2016 at 12:46
  • 1
    $\begingroup$ @Shadock It's intermediate not transition state; otherwise you'd be right. $\endgroup$
    – Mithoron
    Mar 5, 2016 at 14:58
  • $\begingroup$ @Mithoron Non-isolated intermediates are typically written in brackets. Transition states are written in brackets and include the double-dagger notation. $\endgroup$ Mar 5, 2016 at 18:17
  • $\begingroup$ I actually made a lot of technical mistakes. I hope this fixes them. My ChemDraw file got corrupted, so I had to do it all over again from scratch... $\endgroup$
    – ringo
    Mar 6, 2016 at 5:18

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