DAT Destroyer 2014 OChem Question #29

[woosh]

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question goes like..

A student wanted to synthesize the following molecule from benzene:
(-NH2 and -Cl in meta position to each other on a benzene ring)

Which sequence of reagents would be employed?

a) Cl2, FeCl3; HNO3, H2SO4; H2, Pt
b) HNO3, H2SO4; H2, Pt; HNO3, H2SO4
c) HNO3, H2SO4; Cl2, FeCl3; H3O+; OH-
d) HNO3, H2SO4; Cl2, FeCl3; H2, Pt
e) more than one of these


the answer is D. However, what would happen if the reagents of choice C were to be performed?
would one of the oxygens from the -NO2 group be protonated with H3O+, and get deprotonated back to -NO2 with OH-?

 

[ixyz]

nothing would happen during the last step. H3O+ and -OH don't do anything to the nitro group and don't act as reducing agents

 

[gec]

Then why is (A) wrong...?
What would that sequence yield? 😢

 

[dhk2131]

Halogens on a benzene are ortho/para directors but deactivate the ring. Putting on Cl first would direct the nitro group to an o/p position.

 

[tooth knockn]

This question could be on the DAT?

 

[gec]

Halogens on a benzene are ortho/para directors but deactivate the ring. Putting on Cl first would direct the nitro group to an o/p position.

^Ah, you're right -- totally forgot about that rule!
I remembered that Halogens were indeed deactivating, but forgot that they're actually ortho-para directing...

Thank you 🙂

 

[chemkay]

This question could be on the DAT?

Yes. EAS is a small portion of the DAT. Once you learn which are activating/deactivating it's not too bad. Now it's SN1/SN2/E1/E2 that I hate..... Grrrrrr