Does this have to be your starting material?
The issue, as I see it, is that the NO
2 tends to deactivate the ring quite strongly. Indeed, Friedel Crafts Acylations are sometimes conducted using nitrobenzene as the solvent.
Carbonyl's also deactivate the ring quite strongly too, that is why the Friedel Crafts does not often acylate the aromatic ring twice.
How about using NBS to brominate the aromatic ring?
That I don't know, I would have to open this up to one of my colleagues who may have experience of this. If I wanted this molecule, for example:
I would chose another starting material and go
via another route.