3
$\begingroup$

When chlorobenzene ($\ce{C6H5Cl}$) reacts with aqueous ($\ce{NaOH}$) solution it first forms sodium phenoxide ($\ce{C6H5ONa}$), and then phenol upon reacting with $\ce{H+}$.

But my question is, why can't $\ce{Na}$ directly replace $\ce{Cl}$ from chlorobenzene by breaking $\ce{Na-O}$ bond instead of breaking $\ce{O-H}$ bond?

$\endgroup$
  • $\begingroup$ You mean the Na from the NaOH? $\endgroup$ – Simon-Nail-It Mar 5 '16 at 9:15
  • 8
    $\begingroup$ Can you clarify what you think the mechanism is for this reaction? I don't quite understand your question. $\endgroup$ – bon Mar 5 '16 at 13:34
  • $\begingroup$ @Simon-Nail-It Yes sir, Na from NaOH $\endgroup$ – TheNewGenGamer Mar 5 '16 at 15:19
  • $\begingroup$ So your question is why can't $Na^{+}$ react directly with chlorobenzene instead of reacting with phenol? $\endgroup$ – Rok Narobe Mar 5 '16 at 15:57
  • $\begingroup$ @RokNarobe No sir, i mean to say that why is the long process used when we can just break the C-Cl bond in benzene and then Na+ can react with Cl to form NaCl and phenyl cation can react with OH- to give phenol. Why is Sodium Phenoxide is being formed before giving phenol ? $\endgroup$ – TheNewGenGamer Mar 11 '16 at 15:04
4
$\begingroup$

The mechanism of this reaction is that $\ce{NaOH}$ being a strong base with some extreme conditions abstracts H from C adjacent to C containing Cl while Cl also leaves.

This creates benzyne as an intermediate.

Subsequent addition of $\ce{NaOH}$ forms the phenoxide ion.

| improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.