A series of questions on aromatic reactions.
Posted Mar 30, 2017, 7:59 PM UTC
28
Hey all,
I'm having trouble with figuring out these 3 questions. Can anybody give me some pointers?
Thanks in advance!
1
NO2 is electron withdrawing- visualize the resonance structures and you'll see that it will substitute a new NO2 in the meta position.
2
Thank you!
2
You're right! Sorry I fucked up on that!
2
As for the chlorobenzene, the chloro group is deactivating through inductive effect but 2,4 directing through resonance effect - try drawing the mechanism out to see
1
You have three aromatic polysubstitution reactions, you need to understand if the functional group that's already on the ring is electron donating (it pushes electrons on the ortho and para positions of the benzene ring and makes it easier for the electrophile to be attracted) or if it's electron withdrawing (it pulls electrons away from the benzene ring, with the delocalization of a positive charge on the ortho and para positions that repels electrophiles). Whether a functional group is electron donating (activating) or electron withdrawing (deactivating) depends on its resonance structures and electronegativity. Pro tip: be careful with halogens, they can be false friends in this reaction.
Edit: feel free to ask if I wasn't clear enough
I figured out 1 and 3, but what happens if you already have a nitrate group on the benzene ring and you're adding another nitrate group onto it? Would it create the two para and ortho products like in 1 and 3?
Yes, of course. It's just another ED functional group, which means it will direct the reaction in ortho/para.I fucked up