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zed
International Hazard
Posts: 2277
Registered: 6-9-2008
Location: Great State of Jefferson, City of Portland
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Mood: Semi-repentant Sith Lord
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Well, the idea of deconstructing @Amino-Acids as a synthetic method has gained popularity, only fairly recently.
Not economically practical for most materials, but very useful for a few.
We knew the method had potential when I was a student decades ago. But, thousands of monkeys, had to try thousands and thousands of experiments, to
figure out how to make it practical. That's how Org. Chem. goes... It's a group effort.... Involving generation after generation, of failed
experiments.
Edison figured there would be some way to get lightbulbs to work. But, it took thousand of tries, to get it right.
Eventually, guys figured out that these reactions could be conducted at reasonable temperatures, when catalyzed by Ketones. The @Imino-Acid being
the critical intermediate. Other types of decarboxylations work too, we just aren't sure exactly why.
Probably, somewhere in the literature, or in experiments, someone has noted this PABA decarboxylation before, and it probably wasn't deemed very
useful, or economical. Times have changed.
With the current difficulties associated with obtaining reagents, it's very useful. Very useful, and apparently very "Green".
I'm going to check on the "Green" part...... I'll be back!
Zzzzzzzzzzzzzz.
OK..... I'm back.
Wiki suggests traditional PABA manufacturing methods may not be highly evolved, but the fact I can buy it from my Health Supplements company, suggests
that some of it, may currently be manufactured in a manner similar to my other Amino-Acids..... By Fermentation.
https://patents.google.com/patent/US20170211104A1/en
So.... Aniline. But, no need for Nitric Acid, No Sulfuric Acid, No Benzene. No Nitro Benzene.
No Dissolving Metal reductions. No Nobel Metal Catalysts.
No Hydrogen.
Not that Aniline isn't plenty nasty enough on its own, but a broad spectrum of other potential pollutants, can be spared use.
Nice!
................................................................................
Now, Draculic.... Some of your posts, suggest you are a teacher. That's a good thing. But, I found in my former academic background, decades ago,
that federal authorities were hounding us about reagent use.
Does this situation still exist? We got menacing calls about our use of a small amount of Benzaldehyde. And, there was a stink regarding... about a
dozen other common reagents too. And, though the use of these items was entirely innocent, it was still quite a stink.
We had a local DEA "Control Agent" that was downright accusatory.
And then, there was the ATF.
Every month or so, the ATF used to send an agent, to measure the use, of our yearly Gallon or Two, of Absolute Ethanol. He was always complained we
were using "Too much".
We begged our Chemical suppliers to just let us pay the beverage tax, so we would be left alone, but no.... None of them could do that. And, we
weren't in an "Everclear" State.
Experiments screw up, when you use most of the "approved" denatured Alcohols. They aren't fit to drink, but they aren't fit for use in Organic
Chemistry Experiments either.
Ketones, Aldehydes, Esters, Hydrocarbons.
At your institution, do you currently enjoy relative freedom, or are you boggled by regulatory harassment?
Many of the traditional Org. Chem. Reagents are now either "Listed" or considered highly suspect. If this hyper vigilance still exists, it could be
hard to pick out doable experiments.
There are just so many illicit drugs now, it seems like damned near every organic reagent is a potential precursor.
I miss the lab, and I might consider providing lab instruction at a local college, but if the environment is as nutty as it was at my last stop, I'm
out.
What is the Water like?
[Edited on 6-3-2021 by zed]
[Edited on 6-3-2021 by zed]
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draculic acid69
International Hazard
Posts: 1371
Registered: 2-8-2018
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Nope not a teacher, so cant add any thing there.
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nomcopter
Harmless
Posts: 3
Registered: 7-3-2022
Location: California, USA
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Quote: Originally posted by draculic acid69  | | Quote: Originally posted by Nicodem | In literature there are only examples using the Cu/quinoline method for decarboxylating p-aminobenzoic acids (for example: Synthesis (1985)
778-779; JACS, 129 (2007) 4824-4833).
You can't just heat a carboxylic acid and expect it to decarboxylate just like some magic thing. There must be a viable mechanism, either a SET
mechanism as in Cu/quinoline method or one of the several other mechanistic possibilities, but all are substrate specific (none is general).
PS: I'm moving this thread to the Beginnings section due to the original poster not using references and obviously not using neither the search engine
or literature. |
Does anyone else believe this or have doubts?
https://m.youtube.com/watch?v=S0T-sR-nn2Y |
Attempted this today and it appears to have worked and produced fairly pure Aniline. It redistilled nicely at 183C and passed the same tests that
Corrosive Chemistry performed.
None of the obvious oxidation products have a boiling point anywhere near Aniline so I'm going to call it a success! Truly a trivial procedure in
comparison to the sodium benzoate -> benzene -> nitrobenzene -> aniline route. I got 50g or so in just a couple hours of effort for <$20
of materials.
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draculic acid69
International Hazard
Posts: 1371
Registered: 2-8-2018
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It really is the better route
| Quote: Originally posted by nomcopter |
None of the obvious oxidation products have a boiling point anywhere near Aniline so I'm going to call it a success! Truly a trivial procedure in
comparison to the sodium benzoate -> benzene -> nitrobenzene -> aniline route. I got 50g or so in just a couple hours of effort for <$20
of materials. |
It really is a better route all round.
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