How to convert benzene to 1-bromo-3-iodobenzene?

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


I tried something like:


[![synthesis](https://i.stack.imgur.com/qcWzq.png)](https://i.stack.imgur.com/qcWzq.png)


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




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](https://i.stack.imgur.com/5XqIO.jpg)](https://i.stack.imgur.com/5XqIO.jpg)


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