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JJay
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OTC Oxalyl Chloride Challenge
I think we can all agree that oxalyl chloride is an interesting and useful reagent. It's not that hard to make, but most of the readily accessible
syntheses require using phosphorus. While phosphorus is a chemical within reach of many amateurs, it is even harder to obtain than oxalyl chloride,
and it cannot be obtained in all jurisdictions. For this reason, as well as other reasons, it would benefit many amateurs to have a working synthesis
for oxalyl chloride that does not require any phosphorus compounds. Obviously, it would also be best to avoid using chlorinating agents like thionyl
chloride unless they can be generated from readily available chemicals.
So I'm tossing around the idea of running a contest around finding a workable amateur synthesis for oxalyl chloride. An ideal synthesis would involve
the use of only OTC compounds, but it would be more or less equally desirable to have one using only common reagents can be easily obtained online.
I'm not really sure what I can offer for a prize for this challenge... the only rare and exotic chemical I have in quantity is sodium ethyl sulfate
monohydrate... perhaps a small quartz distillation flask would be a suitable trophy?
What would be a suitable prize for such a challenge?
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Sulaiman
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I guess that you will have to specify "OTC" first,
e.g. I buy almost everything, other than food, online,
does mail-order available to the public count ?
Or, if you're going for 'clandestine', cash-only sales ?
by region;
e.g. here in UK I am allowed red phosphorous, oxalyl chloride and thionyl chloride*,
but not oxalic acid >10% w/w 
other members cannot legally purchase sulphuric acid, etc.
so, I for example should have little difficulty in obtaining whatever starting reagents are the most convenient,
whilst others may have to boil-dowm battery acid, do a non-trivial plant extraction ..... etc.
not a level playing field.
* provided that I produce less than 30 tonnes per year, which would make it a Schdule 3 substance under the Chemical Weapons Convention
[Edited on 20-5-2017 by Sulaiman]
CAUTION : Hobby Chemist, not Professional or even Amateur
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Texium
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I would disagree that phosphorus is "even harder to obtain" than oxalyl chloride, as I own phosphorus that I was able to easily purchase online, while
I have not been able to find a source of oxalyl chloride that is available to amateurs (as in it's only for sale from companies like Sigma and Acros).
It's a shame, I've been wanting to make some TCPO. Making PCl5 seems like such a hassle.
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Crowfjord
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Elemental Scientific sells it as a special order chemical. Or did they go out of business? Doesn't look like the site has updated since November, and
I don't recall Tom having posted for a while.
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Texium
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They haven't gone out of business, but they haven't done special orders in a long time. The things on the current list have been out of stock ever
since the last time he organized one.
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clearly_not_atara
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I suggest using SCl4.
This species is generated by the reaction of sulfur with two equivalents of liquid chlorine. It decomposes to SCl2 and Cl2 above -30 C. Hydrolysis is
very exothermic; it might be possible to make SOCl2 this way, but I know of no successful report. It reacts with AlCl3 to give trichlorosulfonium
tetrachloroaluminate which is stable to somewhat higher temperatures but most refs about SCl3AlCl4 are in German.
The challenge is to find a way to dissolve oxalate salts at those temperatures and a solvent you can do it in. The best approach looks like an ionic
liquid or deep eutectic solvent where neither component will react with SCl4, and particularly the case where one of the components is a metal halide
seems interesting. I believe CrCl3/tetramethylammonium chloride or CrCl3/dimethylimidazolium chloride is a candidate solvent here.
So my suggestion is the reaction of oxalate salts with SCl4 or a stabilized derivative in an ionic liquid comprising a metal chloride and a quaternary
ammonium chloride.
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gdflp
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Understandable, really. It seemed like a hassle for them and I can't imagine there was ever a huge demand.
They've always been very helpful when I've spoken to them though, so I'm sure they'd be more than willing to help if you contacted them directly.
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j_sum1
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When did gdflp become super moderator? Congratulations.
[Edited on 21-5-2017 by j_sum1]
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Assured Fish
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Well since TCT (cyanuric chloride) can chlorinate oxalic acid to oxalyl chloride, i would imagine this would be the most OTCish way to go about
preparing your oxalyl chloride.
Of coarse preparation of cyanuric chloride is not something to be taken lightly. Typically its prepared by trimerization of cyanogen chloride over a
catalyst. Cyanogen chloride could be prepared by carefully adding an aqueous solution of sodium cyanide to an aqueous solution of chlorine at a low
temp, followed by a rather frightening low temperature distillation and drying.
I can see no reason why all of this could not be achieved by a determined chemist with a good quality respirator working outside or in a fume hood
although im not evoking anyone to try.
Personally if i were going to attempt something like this id rather work with cyanogen bromide given the higher BP and lower volatility.
Everything required to do such a preparation could be bought over the counter: TCCA, oxalic acid, HCl etc. My only exception would be for the
trimerization catalyst to which i have no idea what sort of carbon catalyst we would require here, i have not been able to find much information on it
although i haven't tried very hard, but typically trimerization of alkenes is accomplished using a catalyst such as palladium on carbon Pd/C.
I did find this but i don't have access to it:
http://onlinelibrary.wiley.com/doi/10.1002/14356007.a08_191/...
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JJay
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I should clarify that routes involving phosgene are disallowed, even if you make it yourself. Chemicals available by mail order to the public can be
used within reason, but it must be possible to carry out your synthesis without purchasing any chemicals from clandestine sources or chemical
suppliers. So bleaching powder, permanganate, nitric acid, etc. are fine, but alkali metals and borohydride are borderline. Building blocks are out,
as are all exotic reagents typically only used by professional chemists, unless they can be made by amateurs. Chemicals available from soapmaking
companies, pottery suppliers, pyro suppliers, nuclear hobby companies, biodiesel supply, flavoring manufacturers, Asian distributors, etc. are fair
game.
You can make oxalic acid from OTC materials if necessary, but this is not required. I would like to be as fair as possible, but the aim of this
challenge is to discover a working route to produce oxalyl chloride, and this may not be possible or legal everywhere, and it is solely your
responsibility to ensure that you have whatever licenses or authorizations you may require to attempt the challenge or win the prize. Obviously, a
fully OTC synthesis of oxalyl chloride using only simple beakers would be what is most desired, but online purchases and sophisticated equipment are
permitted.
The prize will be a quartz distillation flask, with judging to take place on September 1. It will be delivered to whatever address you specify,
anywhere in the world, by parcel post. To win the challenge, you must actually produce some oxalyl chloride using your proposed synthesis.
[Edited on 21-5-2017 by JJay]
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JnPS
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Already looking up old patents and bugging professors for copies of ancient ACS articles, I'll be on vacation for a little over a week, but once I get
back, this will be a fun way to start off my summer break. Thanks for the challenge JJay!
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Sulaiman
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Just in case anyone interested missed this thread http://www.sciencemadness.org/talk/viewthread.php?tid=8742
CAUTION : Hobby Chemist, not Professional or even Amateur
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Melgar
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Oxalic acid should be accessible by carefully adding potassium permanganate to ethylene glycol. Manganese will then form a water-soluble oxalate salt
with it, which spares you the annoyance of having to deal with MnO2 crud. It's also a nice visual indicator of the reaction progress. This most
likely oxidizes quite a lot to CO2 as well, but at least antifreeze is pretty cheap.
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theAngryLittleBunny
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Quote: Originally posted by Melgar  | | Oxalic acid should be accessible by carefully adding potassium permanganate to ethylene glycol. Manganese will then form a water-soluble oxalate salt
with it, which spares you the annoyance of having to deal with MnO2 crud. It's also a nice visual indicator of the reaction progress. This most
likely oxidizes quite a lot to CO2 as well, but at least antifreeze is pretty cheap. |
But potassium permanganate isn't cheap, you need to take 8 elecrons from an ethylen glycol in order to turn it into oxalic acid one KMnO4 takes 5
electrons if the MnO2 oxidizes as well, so you need 1.66 KMnO4 for every ethylen glycol, which is a ratio of about 25:6 of potassium permanganate to
ethylen glycol, so your problem won't be the antifreeze. I think a much better methode would nitric acud + cane sugar, like nile red did.
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Melgar
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| Quote: Originally posted by theAngryLittleBunny | | But potassium permanganate isn't cheap, you need to take 8 elecrons from an ethylen glycol in order to turn it into oxalic acid one KMnO4 takes 5
electrons if the MnO2 oxidizes as well, so you need 1.66 KMnO4 for every ethylen glycol, which is a ratio of about 25:6 of potassium permanganate to
ethylen glycol, so your problem won't be the antifreeze. I think a much better methode would nitric acud + cane sugar, like nile red did.
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Where I am, nitric acid isn't cheap or easy at all, and separating all that is a big mess. My thought was just to go with stuff that most people
would have on hand, and would have an easy workup. If you want to go even cheaper though, then how about chlorine bleach and antifreeze? No need to
waste nitric acid.
Also, what do you think the yield is oxidizing cane sugar to oxalic acid? Far more of that carbon is going to be oxidized to CO2 than oxalic acid.
For an easy workup, you'd probably want to overdo it on the nitric acid, so you could evaporate the residue, which I don't recommend doing if there's
anything metal in the vicinity.
Incidentally, the next time someone cites a Youtuber as though they were the one who discovered a particular reaction, I think I'm going to punch
whoever happens to be next to me at the time. I'm not sure why it annoys me so much, but it does.
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clearly_not_atara
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KMnO4 cleaves most diols. Won't it also cleave ethylene glycol? CrO3 et al seem better.
It might also be possible to oxidize ethylene glycol with only chlorine. Products however may include phosgene.
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j_sum1
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I promised myself I would get involved with the next challenge. But this one is out of my league for the moment. And besides I have no need for
oxalyl chloride. I love the idea of a challenge though. It's been a while since we had one and even longer since we had one that had a high
participation level.
I thought oxalic acid was pretty readily available in most places. If you can't get it then you would want a way of making it at reasonable purity at
reasonable volume with minimal time and expense. And I guess that does depend a lot on what is available where you live. To my thinking, nitric acid
and cane sugar is a more accessible route than propylene glycol and permanganate. But both seem a waste of reagents. I am not sure what the other
options are.
@Melgar
I don't share your dislike for YT citations. I think there is a place for them. Obviously I would not use them for a scientific paper. But in the
realm of amateur chemistry they serve as a good way to cite a procedure. Ours is a pretty visual science and a lot can be learned by watching actual
practice. If someone wished to investigate the production of OA from sucrose, NileRed's video is not a particularly bad place to start. Of course it
is not going to give the depth of a literature survey. But in this case the goal seems to be to get hold of a starting reagent. In that case, depth
is not really required. But a working procedure is. 15 minutes watching a video is going to get me that quicker than trawling through a pile of
scientific papers or patents.
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Melgar
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| Quote: Originally posted by clearly_not_atara | KMnO4 cleaves most diols. Won't it also cleave ethylene glycol? CrO3 et al seem better.
It might also be possible to oxidize ethylene glycol with only chlorine. Products however may include phosgene. |
Oh, oxalic acid is definitely not stable in the presence of KMnO4, however by that point you typically have MnO2, not KMnO4. And even that will
oxidize oxalic acid, reducing itself to the +2 oxidation state. It's not a particularly practical reaction, but it is a pretty cool one to watch, I
have to say. In this sort of competition, you just have to prove a reaction works and is OTC, no?
As far as oxidizing ethylene glycol with chlorine, I believe you're thinking of the similar reaction between benzyl alcohol and chlorine, no? However
I think benzyl alcohol is a special case, and most alcohols don't do that. However, I'm not 100% sure on this one.
| Quote: Originally posted by j_sum1 | @Melgar
I don't share your dislike for YT citations. I think there is a place for them. Obviously I would not use them for a scientific paper. But in the
realm of amateur chemistry they serve as a good way to cite a procedure. Ours is a pretty visual science and a lot can be learned by watching actual
practice. If someone wished to investigate the production of OA from sucrose, NileRed's video is not a particularly bad place to start. Of course it
is not going to give the depth of a literature survey. But in this case the goal seems to be to get hold of a starting reagent. In that case, depth
is not really required. But a working procedure is. 15 minutes watching a video is going to get me that quicker than trawling through a pile of
scientific papers or patents. |
I think the annoying thing is the fact that I learned all this stuff back before these Youtubers had their videos, so when someone tells me "like
NileRed" or "like NurdRage", I've usually read about the procedure already, and for a quick refresher, skimming a paper to the relevant part will be
MUCH faster than watching a 15-minute youtube video. In chemistry, there's already a set of named reactions, AND NONE OF THEM INCLUDE THE NAMES
"NURDRAGE" OR "NILERED"!!!! Ok, sorry, I needed to get that off of my chest.
[Edited on 5/22/17 by Melgar]
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j_sum1
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Point taken. It's not like these guys have ownership of the procedures. (Although Nurdrage has developed some novel processes and deserves some
credit.) It just ends up being a convenient handle to refrence the information. Too convenient perhaps.
I'll try to be a bit more careful and avoid phrases like "Cody's process". But I do confess that I have learned an awful lot in a short time from YT
channels. Given that input it seems a sensible thing to discuss.
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Sulaiman
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As a pure amateur I have to say that YouTube videos have been invaluable to me,
it is so helpful to have an informal medium where tips, tricks, warnings etc can be disseminated,
and to see what should (or may) happen before I try gives me more confidence to try things myself,
YT has generated enough cash for some that they can afford to do stupid or exotic experiments and show me in detail, wonderful.
One semi-negative aspect,
sometimes I have an interrest in a reaction so I watch a few YT vids on it,
often I have learned enough from the vids to not bother doing the reaction myself !
EDIT: it is just like cookery;
. personal tuition to boil an egg
. video for process control
. books with pictures for intermediate level
. textbooks for the initiated
. exotic ancient recipies for the enthusiast
etc.
all are useful
[Edited on 22-5-2017 by Sulaiman]
[Edited on 22-5-2017 by Sulaiman]
CAUTION : Hobby Chemist, not Professional or even Amateur
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Chemetix
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YT has a long way to go to topple the heavyweights of name reactions, and the H.W.Z. does definitely not need another name attached. Huang - Minlon-
youtoober variant number 403 is not something I want to see either. But back to the point... umm why Ox chloride ? I don't seem to get the importance
of this one.
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byko3y
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The reason why i don't even try to make videos is because text and few pictures are much more informative than watching a video. 5-20 seconds of video
might be needed, but that's more than enough.
Many of those making youtube videos actually fail to ascertain the quality of the product, and some even don't bother with idendification at all.
That's the result of focus on making video and not on making a reaction product. For this reason it would be great if someone made some new-age
picture- and video-assisted guides on preparatory methods while being guided by a hardcore autistic experimentalist.
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JJay
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Oxalyl chloride is interesting in that it can be used to make glowsticks. Also, it is a mild chlorinating agent, or at least it is more mild than many
other chlorinating agents. In addition, it is less regulated than certain other chlorinating agents like thionyl chloride, which have historically
been used to make chemical weapons. It raises fewer eyebrows than phosphorus oxychloride/trichloride/pentachloride because it doesn't contain
phosphorus. And it's not nearly as dangerous as phosgene.
A clear writeup specifying reaction conditions and yields is probably easier to follow than a YouTube video, but there is something to be said for
actually seeing a successful reaction take place. Often, written procedures are vague or simply don't work exactly as described, and it is certainly
much easier to watch a 15 minute YouTube video than to spend several hours compiling documents and doing calculations before running several trial
experiments to find something that works.
I think a 500 mL quartz distillation flask is a suitable trophy, and I think that home chemists definitely want to know how to make oxalyl chloride
using readily available chemicals. That is why I am running this challenge.
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Melgar
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To be fair, I have nothing against the YouTubers themselves, only people who reference procedures from their videos by the YouTuber's name, as opposed
to the actual name of the reaction.
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theAngryLittleBunny
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| Quote: Originally posted by Melgar | | To be fair, I have nothing against the YouTubers themselves, only people who reference procedures from their videos by the YouTuber's name, as opposed
to the actual name of the reaction. |
The actual name of the reaction, hmm....as far as I know, I don't think there is a name for the oxidation of sugar by nitric acid, but please correct
me if I'am wrong. And I didn't know that you're 13 years older then me and therefore probably much more experienced. As others said, I rather like to
see the whole procedure, because I generally like to know exactly what to expect before doing it myself. But if you you're more experiwnced, reading a
paper is much more efficient.
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