Triflic Acid
Hazard to Others
Posts: 486
Registered: 27-9-2020
Member Is Offline
Mood: Slowly Oxidizing into Oblivion
|
|
OTC Oxalyl Chloride?
It says on organic chemistry portal that tert-butyl hypochlorite reacts with aldehydes to form acid chlorides. https://www.organic-chemistry.org/chemicals/oxidations/tert-... So, I was thinking, since tert-butyl hypochlorite is not that difficult to prepare
OTC, start with Methyl tert-butyl ether, a gasoline additive, hydrolyze to t-butanol. Then react with hypochlorite to make the t-butyl hypochlorite.
Passing ethylene glycol over copper oxide at 250C gives anhydrous glyoxal according to https://patents.google.com/patent/US4282374A/en. So, if you built an apparatus that boiled ethylene glycol in one flask, passed that over hot
copper oxide in a tube, then condensed the glyoxal into a small three neck flask with a drying tube on one neck, the condenser on the middle neck, and
an addition funnel of the t-butyl hypochlorite. Adding the hypochlorite slowly gives oxalyl chloride. Distill this to get the pure compound. Would
this work as an OTC method to oxalyl chloride, since there aren't any non OTC chemicals needed.
|
|
|
njl
National Hazard
Posts: 609
Registered: 26-11-2019
Location: under the sycamore tree
Member Is Offline
Mood: ambivalent
|
|
The link you have to organic-chem doesn't work for me. MTBE isn't exactly otc since I don't think you can buy it in any significant quantity (pure)
but it isn't that difficult to make. Glyoxal is notoriously difficult to deal with. On top of all of this, you need very dry reagents and if you're
using hypochlorite (likely in aqueous solution) this might be difficult to achieve. I don't think this would be a good route to oxalyl chloride, but
maybe it would work for acetyl or benzoyl chloride since they are easier to handle and are more stable.
|
|
|
clearly_not_atara
International Hazard
Posts: 2692
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
| Quote: | | start with Methyl tert-butyl ether, a gasoline additive, hydrolyze to t-butanol. |
MTBE is infamously foul-smelling and -tasting, and you'll need careful control to avoid generating isobutylene instead.
"vapor-phase oxidation of ethylene glycol with oxygen over a copper-containing catalyst and in the presence of a phosphorus compound which is
volatile under the reaction conditions"
Heating a mixture of flammable gas + oxygen would not usually be my first choice for a chemical synthesis. It does work well in industrial reactors
with careful control of flow rates + stoichiometry + temperature but if one of those variables goes the wrong way, you can make a loud noise and a
mess. There are plenty of other ways to make glyoxal that you can find by Using The Forum Search Engine.
| Quote: | | It says on organic chemistry portal that tert-butyl hypochlorite reacts with aldehydes to form acid chlorides |
This is a free-radical halogenation. As such, any source of Cl* radicals will do. However, it is important to consider whether scission of the C-C
bond in glyoxal is possible with a Cl* radical. What do you suppose would be the side-product in that case?
[Edited on 04-20-1969 by clearly_not_atara]
|
|
|
Triflic Acid
Hazard to Others
Posts: 486
Registered: 27-9-2020
Member Is Offline
Mood: Slowly Oxidizing into Oblivion
|
|
@ clearly not atara, I didn't think about the danger of phosgene production. That scares me out of testing this. Also, what other ways of making
glyoxal create anhydrous glyoxal? I think this is the only one that doesn't need P2O10. Maybe there would be a way to stop the phosgene side reaction?
|
|
|
njl
National Hazard
Posts: 609
Registered: 26-11-2019
Location: under the sycamore tree
Member Is Offline
Mood: ambivalent
|
|
If you want to add a radical scavenger you're really getting away from the OTC premise. Phosgene isn't even the only issue, you would likely get HCl.
phosgene, carbon monoxide, water (destroying your target compound), and a whole lot of tar. Glyoxal is simply not the right substrate for this
reaction.
Reflux condenser?? I barely know her!
|
|
|
Triflic Acid
Hazard to Others
Posts: 486
Registered: 27-9-2020
Member Is Offline
Mood: Slowly Oxidizing into Oblivion
|
|
What would be a better substrate?
[Edit: Second Question: Is there another acid chloride that will react with oxalic acid to produce oxalyl chloride?]
[Edited on 22-2-2021 by Triflic Acid]
|
|
|
mackolol
Hazard to Others
Posts: 458
Registered: 26-10-2017
Member Is Offline
Mood: Funky
|
|
Quote: Originally posted by Triflic Acid  | | @ clearly not atara, I didn't think about the danger of phosgene production. That scares me out of testing this. Also, what other ways of making
glyoxal create anhydrous glyoxal? I think this is the only one that doesn't need P2O10. Maybe there would be a way to stop the phosgene side reaction?
|
Well, phosgene is generated as a side product in almost any oxalyl chloride synthesis I believe as a byproduct. It's just a matter of how much of it
is generated in particular syntheses.
The other thing is, that oxalic acid, being the shortest dicarboxylic acid doesn't behave like your normal acid. It's much harder to make its chloride
than any other acyl chloride. For example you won't make the oxalyl chloride from SOCl2 as you would with other carboxylic acids.
The t butyl hypochlorite, there is a big chance that won't do too.
Don't you have an access to t butanol by the way?
|
|
|
Triflic Acid
Hazard to Others
Posts: 486
Registered: 27-9-2020
Member Is Offline
Mood: Slowly Oxidizing into Oblivion
|
|
I do have access to t-butanol. I was just showing how t-butanol could be made to make this a fully OTC synth. Is there another acid chloride that will
react with oxalic acid to produce oxalyl chloride?
[Edited on 22-2-2021 by Triflic Acid]
|
|
|
karlos³
International Hazard
Posts: 1520
Registered: 10-1-2011
Location: yes!
Member Is Offline
Mood: oxazolidinic 8)
|
|
You know how instable tert-butyl hypochlorite is?
Use a rubber stopper and it just goes *boom!*.
I wouldn't want to work with it on bench scale, especially not selfmade in a home lab, if I would get ten times my hourly salary back when I still
worked as lab chemist.
Bought, well maybe, but a blast shield would be my friend for any reactions with it.
|
|
|
Triflic Acid
Hazard to Others
Posts: 486
Registered: 27-9-2020
Member Is Offline
Mood: Slowly Oxidizing into Oblivion
|
|
If you won't but a rubber stopper in it, how about a all natural cork  . Nobody
has answered my question yet though, is there any other acid chloride that reacts with oxalic acid to make oxalyl chloride?
[Edited on 22-2-2021 by Triflic Acid]
|
|
|
karlos³
International Hazard
Posts: 1520
Registered: 10-1-2011
Location: yes!
Member Is Offline
Mood: oxazolidinic 8)
|
|
Thionyl chloride or phosphorus chlorides of course.
The former is OTC, in batteries... at least in russia.
|
|
|
mackolol
Hazard to Others
Posts: 458
Registered: 26-10-2017
Member Is Offline
Mood: Funky
|
|
| Quote: Originally posted by karlos³ | Thionyl chloride or phosphorus chlorides of course.
The former is OTC, in batteries... at least in russia. |
Thionyl chloride ain't gonna work: https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
Only PCl5 and of course cyanuric chloride (TCT), but you will have a lot of fun with exothermicity of the reaction with latter.
[Edited on 22-2-2021 by mackolol]
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
