AC would need to be no less than 55-60 though when fully buffed and there would bee a lot of hasting and running involved but it could be done.
Need about 3 Avasculates, Greater Magic Missile Empowered 2-3, Lesser Magic Missile Maximized about 2-3, Orb of Force as many as you can fit........
Now, when you run out of offensive spells, or haste......
Elemental Shield Extended, Death Armor Extended and finally Tenser's extended going to work with ranged weapons if possible, or sword & board to up the AC.
Offensive spells alone won't do it but if you can get him down low enough, hang on and hope by hitting you he is damaging himself as well as you......
You might have a chance