lybra0076
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functional groups on a benzene ring
I am trying to do a synthesis with starting with a benzene ring. I pretty much have it figured out. I am adding NO2 onto the ring because it directs
ortho and para, then, because I want to add CHO in the orth position, I need to add something else that will add in the para position. The two
questions that I have go together 1. what group 2. how do I disconnect it after its use.
long story short....
I am not really aware of any disconnections of a functional group from on a benzene ring.
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bbartlog
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Although I don't know much about organic synthesis, I don't believe that it is normally a practical approach to use a protecting group (which is more
or less what you're trying to do) in order to protect the para position or any other unmodified place on the benzene ring, simply because selectively
removing whatever it is will be too difficult. You either need a different approach or else just a good way to separate the ortho and para products.
Also, if you want advice it helps to give more information, like what it is you're trying to synthesize, rather than just some piecemeal clues.
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I am not really aware of any disconnections of a functional group from on a benzene ring. |
Benzoic acid (well, benzoates) can be decarboxylated by heat, and toluene likewise can be stripped of the carbon and turned back into benzene. There
are also other reactions that seem to strip a functional group but I think often the result is a coupling reaction (or just a mess) as for example in
the deamination of aniline to produce diphenylamine.
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entropy51
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I'm not certain what you're trying to do, but you mention a nitro group. Sometimes a nitro group can be removed from the ring by reduction to an
amino group, followed by a diazotization and removal as nitrogen gas by treatment with something like copper powder.
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Nicodem
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Thread Moved
30-9-2010 at 06:25 |
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