5
$\begingroup$

Today, my chemistry teacher gave the following organic conversion as homework: benzene to 1-bromo-3-iodobenzene.

I tried something like:

synthesis

I am not sure about it, can someone review my conversion (as I have got an exam tomorrow)?

$\endgroup$
4
$\begingroup$

It looks pretty good overall. The order of substitution is correct to achieve the required pattern but there are two points I would pick up on.

  1. The final substitution of the diazonium salt is best done with $\ce{CuI}$ rather than $\ce{KI}$ as the copper(I) ions catalyse the reaction. Also heating is not required; the reaction can be run at room temperature (or possible slightly above but not much).
  2. The diazonium salt is drawn incorrectly since it is ionic in nature. There is a triple bond between the nitrogens and a formal positive charge on the middle nitrogen, although in reality the charge is delocalised over both atoms:

    enter image description here

|improve this answer|||||
$\endgroup$
  • 1
    $\begingroup$ Do you have an example using CuI for that reaction? I've actually only ever seen KI for the transformation of diazonium to iodide. $\endgroup$ – jerepierre Aug 6 '15 at 20:07
  • $\begingroup$ Interesting, I assumed that iodide would be similar to chloride and bromide but perhaps I am wrong. No I have never actually seen an example. $\endgroup$ – bon Aug 6 '15 at 20:16

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.