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:

$\hspace{10 mm}$

or:

However, the first route is not possible as the Friedel-Crafts reaction does not yield a meta-substituted product. Why is that so?

• Hmm, I don't like second reaction either, you have proof it would work? – Mithoron Dec 22 '15 at 22:28
• Also, I don't believe Na will leave that nitro group intact. – Ivan Neretin Dec 23 '15 at 6:35

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.

• Agreed. Most undergraduate organic chemistry texts come with a big disclaimer that Friedel-Crafts reactions work poorly on deactivated rings. I would love to see a link or reference for the use of nitrobenzene as a solvent for FC reactions. It would really solidify this answer. – Ben Norris Dec 22 '15 at 18:14
• – ShankRam Feb 8 '16 at 2:15