Sciencemadness Discussion Board

Nitration and acetone

Elemental Phosphorus - 17-7-2019 at 17:42

About 2 years ago, I had an accident in which I mixed a small amount of fuming nitric acid and acetone inside a graduated cylinder. The mixture quickly began bubbling and fuming, and within a few seconds, the contents of the cylinder were ejected onto my ceiling, leaving a nasty blotch. I had wondered why this happened, so today I revisited it, adding acetone to a test tube containing fuming nitric acid. This time, it wasn't as violent (maybe because I added acetone to RFNA, and last time I added RFNA to acetone) but the reaction was still vigorous, ejecting plenty of RFNA and acetone from the test tube, after copious bubbling and production of nitrogen dioxide. Luckily, I worked outside this time. Anyhow, I was wondering if anyone has some sort of insight into how this happens, I'd be interested to hear it. All over the internet, there are reports of injuries and accidents involving acetone and nitric acid. So my question is: is the acetone being oxidized, or is it being nitrated? Is it oxidized directly to carbon dioxide, water and nitrogen, or is there an intermediate?


Finally, I seem to recall that I heard some reference to nitric acid being able to convert acetone to a powerful and sensitive explosive. I thought I saw that on this board. I plan to do a test in which I will attempt to see what product may be produced if I add very cold nitric acid to very cold acetone under strong stirring, and then evaporate the solution. I'll try and post some pictures/videos of the acetone/nitric acid, and this test when I get around to it. Anyway, any response or insight would be appreciated.

Sulaiman - 17-7-2019 at 22:51

Nitric acid plus acetone = formic acid plus acetic acid plus heat
if allowed to heat up then https://www.youtube.com/watch?v=uFwiZYfEsuY

Conc. nitric acid is very oxidising when hot, less so when cool (and/or diluted),
so reactions often start very slowly then suddenly run away.
(usually producing lots of NO2)

Pumukli - 18-7-2019 at 02:55

Isn't formic acid oxidized further immediately? (CO2, H2O, more heat)

Microtek - 18-7-2019 at 11:15

According to US3491160A, acetone can be destructively nitrated to nitroform be fuming nitric acid. I have used this method myself from time to time.

Elemental Phosphorus - 18-7-2019 at 13:21

Now THAT’S what I’m talking about. I’ll try it tomorrow. I’m just worried about an accident or runaway.

Microtek - 19-7-2019 at 10:08

Just add the acetone gradually. The reaction is quite violent (I think I preheated the nitric acid when I did it, but it was quite some years ago, so I'm not entirely certain), and I think I remember some alternate methods, possibly from other patents, which aimed to tame the reaction a little.

Yamato71 - 30-1-2021 at 21:11

I would think that nitric acid would initially go after the alpha carbons and oxidize the ketone to the gem diol. Once that happens, the diol alcohols would undergo esterification, resulting in a mixture of nitromethane, nitroform and tetranitromethane. Very bad juju. I remember performing this only once with 68% HNO3 and watching with fascination as the mixture went through several distinct color changes like a clock reaction before spraying all over the fume hood.

Boffis - 31-1-2021 at 04:48

The reaction of fuming nitric acid with organic materials is complex and the results very diverse. The results range from an instantaneous whoosh (:)) to some remarkable complex derivatives of such things as furoxan. The later compounds are probably produced by the dimerisation of nitrile oxides (fulminic acid derivatives). Certainly one of the original routes into the so-called fulminuric acids (C3N3H3O3 isomers) was via the oxidation of diethyl-acetonedicarboxylate or ethyl acetoacetate to furoxandicarboxylic acid diethyl ester. From this latter compound a bewildering array of heterocyclics can be produced. Some years ago I did a great deal of work on the fulminic and fulminuric acids and I hope hope someday to post it on SM but its a beast already and nowhere near complete. Having tried this route into the fulminuric acid I can see why it was never popular! However, none of the other routes are easier or safer; large amounts of silver or mercury fulminate + large amounts of sodium amalgam etc etc... you get the picture!

I am not sure whether acetone would give the simple furoxan (C2N2H2O2); by extension of the reactions above it ought to but furoxan is actually harder to prepare than its derivatives (its usually prepared via the oxidation glyoxal dioxime) the the various patents mentioned above also suggest otherwise.

Elemental Phosphorus - 16-3-2021 at 15:38

Quote: Originally posted by Yamato71  
I would think that nitric acid would initially go after the alpha carbons and oxidize the ketone to the gem diol. Once that happens, the diol alcohols would undergo esterification, resulting in a mixture of nitromethane, nitroform and tetranitromethane. Very bad juju. I remember performing this only once with 68% HNO3 and watching with fascination as the mixture went through several distinct color changes like a clock reaction before spraying all over the fume hood.


This is interesting, I remember that I said I would try a reaction to produce nitroform and post the results, of course I never did, because I chickened out of making nitroform, and reading your post that says that tetranitromethane may also be produced has made me glad I never did. Tetranitromethane is just one of those compounds that I try and avoid. Interesting that you mention color changes, the only color change I noticed was the pale yellow fuming nitric acid and the clear acetone turned immediately to an angry red color, almost like that of a solution of bromine in DCM. Immediately there was bubbling which I assumed was the production of copious amounts of NO2 gas. Bad juju indeed.

Quote: Boffis:
The reaction of fuming nitric acid with organic materials is complex and the results very diverse. The results range from an instantaneous whoosh (:)) to some remarkable complex derivatives of such things as furoxan. The later compounds are probably produced by the dimerisation of nitrile oxides (fulminic acid derivatives). Certainly one of the original routes into the so-called fulminuric acids (C3N3H3O3 isomers) was via the oxidation of diethyl-acetonedicarboxylate or ethyl acetoacetate to furoxandicarboxylic acid diethyl ester. From this latter compound a bewildering array of heterocyclics can be produced. Some years ago I did a great deal of work on the fulminic and fulminuric acids and I hope hope someday to post it on SM but its a beast already and nowhere near complete. Having tried this route into the fulminuric acid I can see why it was never popular! However, none of the other routes are easier or safer; large amounts of silver or mercury fulminate + large amounts of sodium amalgam etc etc... you get the picture!

I am not sure whether acetone would give the simple furoxan (C2N2H2O2); by extension of the reactions above it ought to but furoxan is actually harder to prepare than its derivatives (its usually prepared via the oxidation glyoxal dioxime) the the various patents mentioned above also suggest otherwise.

[End Quote]

I do think that this is interesting, and I would love to someday read your research on fulminic and fulminuric acids. Maybe I will have to revisit this experiment after all.

I have some videos of the reaction between acetone and the acid, and it really impressed me just how much NO2 is produced. I have tried to attach the video and this is even after the reaction had slowed down just slightly, and there really is an impressive quantity of red fumes.

Edit: I seem to have messed up the quotes. Also, the file is low quality, maybe I can post it on a video site and put a link.
Attachment: Acetone-and-RFNA (615kB)
This file has been downloaded 367 times



[Edited on 16-3-2021 by Elemental Phosphorus]

zed - 18-3-2021 at 01:21

Mmmm..... The way I remember it, Formic Acid can abruptly decompose, in a rather ominous manner.

HCOOH, when you balance the equation of break down, doesn't equal CO2 + H2O.

HCOOH, breaks down to CO + H2O. I'm not sure how often that happens, but CO ain't compatible with lifeforms that utilize Hemoglobin.

https://en.wikipedia.org/wiki/Formic_acid

Catalyzed by Pt, you might get H2 + CO2

Catalyzed by H2SO4, you get H2O + CO

Sorry, but I was unable to read your file. My Mac doesn't understand the format.

[Edited on 18-3-2021 by zed]

[Edited on 18-3-2021 by zed]

njl - 18-3-2021 at 05:47

Formic acid does decompose to CO over time, or via dehydration with H2SO4. Pt, Pd, Ni, etc can all yield H2 and CO2 depending on conditions.

Elemental Phosphorus - 18-3-2021 at 08:08

Quote: Originally posted by zed  
Mmmm..... The way I remember it, Formic Acid can abruptly decompose, in a rather ominous manner.

HCOOH, when you balance the equation of break down, doesn't equal CO2 + H2O.

HCOOH, breaks down to CO + H2O. I'm not sure how often that happens, but CO ain't compatible with lifeforms that utilize Hemoglobin.

https://en.wikipedia.org/wiki/Formic_acid

Catalyzed by Pt, you might get H2 + CO2

Catalyzed by H2SO4, you get H2O + CO

Sorry, but I was unable to read your file. My Mac doesn't understand the format.

[Edited on 18-3-2021 by zed]

[Edited on 18-3-2021 by zed]



No worries about the file, it’s just a (low quality) video of the reaction in a test tube. I am aware that formic acid decomposes to CO and water, but I did not see any evidence of the evolution of CO. Possibly it could be oxidized by another equivalent of nitric acid, but either way, I was really just wondering about the reaction and why it was so violent, because usually nitric acid does not react so vigorously with organic compounds at room temperature, except maybe nitrogen-containing compounds or alkenes. I was really just curious, that’s all, and while Boffis had interesting insight I think I’ll stick to nitric acid oxidations that don’t produce highly toxic or explosive compounds.

Diachrynic - 18-3-2021 at 11:57

Quote: Originally posted by zed  
Sorry, but I was unable to read your file. My Mac doesn't understand the format.

Rename it and append .mp4 and it will play. The file extension just got lost.

As per the reaction, the following paper gives some insight into it. The end product seems to be carbon dioxide and minor amounts of acetic acid.

Rubtsov, Y. I., Kazakov, A. I., Sorokina, T. V., & Manelis, G. B. (2008). Critical phenomena in acetone oxidation by nitric acid. Russian Chemical Bulletin, 57(10), 2065–2071. doi:10.1007/s11172-008-0280-8

Attachment: rubtsov2008.pdf (309kB)
This file has been downloaded 433 times

[Edited on 18-3-2021 by Diachrynic]