I am trying to prepare a Grignard reagent from 4-nitrobenzyl bromide
but the reaction just doesn't work. My conditions are:
- 10 mL of THF (anhydrous);
- 7.04 mmol of 4-nitrobenzyl bromide;
- 7.04 mmol of Mg;
- Argon atmosphere.
Water is not a problem since I left all my glassware in the oven overnight and flame-dried the round bottom flask + stir bar before adding Mg and the bromide. I also did everything under argon. I know the reaction is not proceeding because virtually all of the Mg turnings I added are still there and the solution is still clear. I tried adding two crystals of iodine but it didn't help either.
Is there something about this particular bromide that prevents/slows down the formation of the Grignard? I was wondering if the fact that the nitro group is electron withdrawing could make it more difficult to form the carbanion-like structure of the Grignard.