-NH2 & -NO2 attached to aromatic ring

[adizzle87]

So on Kaplan Orgo Subject test #5, they are saying that NO2 is deactivating (I know that) and that it is meta directing. It's my understanding that NO2 is so strongly deactivating that you can't add anything to it, am I right?

Also it was also my understanding that NH2 is activating, but that it was extremely activating to the point that you can't add anything to it. Am I wrong on this as well? I believe I got this from OChem as a Second Language....

I think I picked up an error on problem #11....I knew that it was Wolf-Kishner and that the carbonyl group would be removed. However all the answer choices were whack....there was only one where the carbonyl was removed but it added an additional carbon to the alkyl group. This isn't suppose to happen right?

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[yankees27th]

What you said about -NO2 is right. -NH3 is activating and that makes it more reactive.

Wolff-Kishner does not add an extra carbon. You are correct. I don't have the question in front of me though so I can't say anything about the choices.

 

[bustedgrill]

could have sworn that NH2 on an aromatic ring cannot have anything added to it. Isn't that the case for all N groups attached?

 

[199868]

What you said about -NO2 is right. -NH3 is activating and that makes it more reactive.

Wolff-Kishner does not add an extra carbon. You are correct. I don't have the question in front of me though so I can't say anything about the choices.

NO2 as we all know is very deactivating because it draws its electrons into oxygens rather than donating them into the benzene ring. NO2 CANNOT undergo Friedel-Crafts acyl and alkylation because Friedl-Craft itself is too slow anyways. NH2 also cannot undergo Friedel-Crafts reaction. Amine will react with the lewis acid(AlCl3) forming a complex, which is deactivating. As for the wolff and kishner, I don't think it "removes" a carbonyl group, rather it reduces it to a methylene(CH2). And NH3+ ISN'T a acitivating group. In fact, it is a deactivating group. I'm thinking that is a typo.

Hope that helps.

 

[adizzle87]

Haha...I knew it. Man, all this conflicting info b/w Kaplan and reality. What to do on the real thing...

 

[yankees27th]

Yeah I meant -NH2 not -NH3.

 

[glk2101]

orgo as a second language is required reading for this topic..helped me get a 26 on orgo