SM2
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Aniline
Years ago, we're talking 25+ years, our lab had a stock including a mostly empty jar of analine. It looked as if it was redenning, and had this
"crayon" stench I will always remember. Short of the classical reduction of 1-nitrobenzene, I've done some research, and found there is an alternate
procedure which starts with phenol, and uses ammonia to introduce th amino group, and also leaves a hydrogen which leaves with the hydroxyl as water.
I have used the search engine, and some of the preps seem a bit complicated. Isn't there a more straight forward way of animating the alcohol? Maybe
straight dry ammonia gas and carboxylic brought to the melting point on a stirrer/heater? I'm still learning here, so any info is most greatly
appreciated.
Thank You!
SM2
"Old men who speak of victory
shed light upon their stolen life
they - drive by night- and act as if they're
moved by unheard music." B. Currie
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Dr.Bob
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By far the simplest approach is nitration and reduction to aniline. I don't know any simple ways to convert a phenol to a aniline. But I am sure
that there may be difficult ways. Ultimately, an amine is often considered the ideal starting point for the conversion to other groups, via the
Sandmeyer or similar reactions.
There are a few ways to convert an acid to aniline, via the acyl azide or primary amide, but most of those methods use hazardous or harder to get
chemicals. Or you could destructively distill (coke) some coal, and fractionate, as coal tar contains come aniline, along with ~1000 other
chemicals. But it used to be practical source.
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SM2
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Analine
Tnx you, Dr. Bob.
"Old men who speak of victory
shed light upon their stolen life
they - drive by night- and act as if they're
moved by unheard music." B. Currie
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Galinstan
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Another fairly iomple way to anailne is the hoffman rearrangement on benzanamide which i have never tried personally but i think i read some where a
while ago that it does work with reasonable yields 
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Mailinmypocket
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See this thread for aniline from benzamide
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Ascaridole
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Phenol is not a good starting material unless you have tons of it you want to use. As for an alternate synthesis to aniline from phenol its a tough
sell. Perhaps using the phenoxide to force the ketone tautomer like in a Kolbe-Schmidt reaction will help in getting a reactive intermediate. Again
its a tough sell especially without forming other garbage along the way.
The benzamide or nitrobenzene method is much more practical as it is a "known" and well studied reaction with acceptable yields.
Perhaps there is an alternate starting material other than aniline to your target compound?
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Nicodem
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Quote: Originally posted by SM2  | | Short of the classical reduction of 1-nitrobenzene, I've done some research, and found there is an alternate procedure which starts with phenol, and
uses ammonia to introduce th amino group, and also leaves a hydrogen which leaves with the hydroxyl as water. |
The Bucherer reaction does not work on phenol.
For obvious reasons, phenol is one of the worst possible starting materials for aniline. However, if one would be forced to use it, the most
applicable route is probably to first make p-nitrophenol from it, then p-nitrochlorobenzene or p-nitrobromobenzene with Ph3PX2 (X = Cl or Br, DOI:
10.1002/cber.19620950232) or PCl5, then hydrogenation over Pd-C to give aniline (plenty of references).
PS: I would appreciate the posters restraining from doing anal jokes about aniline. It is not funny at all. And SM2, please open topics in appropriate
sections according to the instructions in the forum guidelines.
…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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Nicodem
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Thread Moved
7-2-2014 at 05:53 |
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