dennisfrancisblewettiii
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Ph-COOH group to Ph-NO2?
My memory is foggy. I thought this was a possible synthesis, but I cannot recall if it really is. I suspect it is, but I can't figure out how to
convert a carboxylic acid group to a nitro group when it's on a cycloalkane.
I cannot get much luck with google.
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Nicodem
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Thread Moved
2-8-2012 at 07:54 |
Nicodem
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Could you be more specific? Are you asking if it is possible to convert benzoic acid to nitrobenzene in one step? Not really, at least not easily and
in a single transformation.
Or are you asking if the carboxy in the arylcarboxylic acids can be transformed to the nitro group? Well, in some substrates that fit the
requirements, an aromatic electrophilic substitution can be achieved that results in ipso nitration. This is nothing general though.
What do cycloalkanes have to do with your question?
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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dennisfrancisblewettiii
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My apologies. I've forgotten that phenyls are not are not cycloalkanes.
Specificity:
Let's say I find a way to isolate uroporphyrinogen III from blood. And I want to take the R-COOH groups and turn them into R-NO2 groups. What would be a good way to do that?
I guess preferably for my agenda, this situation is that there is really a R1R2-COOH setup whereby I would want a
R1-NO2 setup.
As the title of the tread goes, however, I still would like to know a common lab synthetic route to take Ph-CO2H into Ph-NO2.
[Edited on 2-8-2012 by Genecks]
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Nicodem
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The only good way to such a nitro compound would be total synthesis.
No derivatization could be simpler than a total synthesis, let alone more efficient. If you want to substitute 8 carboxy groups, of two quite
different types and on such a sensitive system, by the nitro group, you can forget about any derivatizations. No derivatization reaction sequence is
selective enough to achieve an efficiency even remotely comparable to the relatively simple total synthesis.
| Quote: | | I guess preferably for my agenda, this situation is that there is really a R1R2-COOH setup whereby I would want a
R1-NO2 setup. |
The carboxy groups in the simplest aliphatic carboxylic acids can be substituted into nitro groups in a single step by applying free radical
nitration, but this requires harsh conditions (gas phase reaction at 200 °C or more). This way nitromethane can be obtained from acetic acid and
nitroethane from propanoic acid. See the thread on the topic of gas phase radical nitration. The reference is posted there.
| Quote: | | As the title of the tread goes, however, I still would like to know a common lab synthetic route to take Ph-CO2H into Ph-NO2. |
Decarboxylation to benzene and nitration to nitrobenzene. Both steps are described in detail on this forum. All it takes is to UTFSE.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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497
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Google nitrodecarboxylation.
Probably won't work on benzoic acid, but it does on some substituted benzoic acids.
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