Why is the Friedel-Crafts alkylation of nitrobenzene disfavoured? Suggest a synthetic route to m-nitrotoluene, starting from benzene.


The conversion can be achieved in two ways:

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or:



However, the first route is not possible as the Friedel-Crafts reaction does not yield a meta-substituted product. Why is that so?
The nitro group is so deactivating that yields are really poor for Friedel-Crafts reactions with nitrobenzene; not even the meta-substituted product is found in good yield. In fact, nitrobenzene is actually used as a solvent in Friedel-Crafts reactions.