mr_bovinejony
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Halosaccharins
I have heard about these halo saccharin compounds a few weeks back but hadn't really looked into them until yesterday. They seem like a way easier way
of adding a halogen group than halo succinimides, mostly because the cheap cost of saccharin and the ability to use halogen salts with oxone. I found
this explanation here:
https://www.scielo.br/scielo.php?script=sci_arttext&pid=...
It all seems just fine, but I have yet to come across any kind of "non-professional" reports of its use and the practicality of its halogenating
properties. Has anyone used these halosaccharins with great success where a halosuccinimide or even just a halogen would be used?
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Boffis
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Interesting find, I must admit that while I have vaguely heard of them before, like you I have never send an article that uses them in a practical
preparation. But certainly worth investigating.
One of the problems I have had with haloimine and imides is the large amount of spent imide that has to be removed from the reaction mixture before
you can recover your product. This is why TCCA is often the best bet, it has three chlorines to donate, the by product is sparingly soluble in almost
everything, its cheap, its OTC and the waste product can be used to prepare calcium cyanamide etc.
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mr_bovinejony
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I've never had that issue with NBS i think, or if I did it was simple enough to remove. But the idea of having a kind of all-purpose halogenating
reagent intrigues me, especially one that can be made with literally salt and sugar in Acetonitrile. Its more gentle than tcca as well, at least from
what I've read.
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karlos³
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They are less good halogenating agents apparently.
But I've never used them for that or any other purpose, I just whipped up a batch of NCSac once and that was it.
Haven't I sent you that paper though, a few weeks ago, where they reported aromatic iodination with NISac?
I am sure I have.
You know the one where they reported it to work better than NIS, the N-iodosuccinimide, for that purpose.
I would say that is a good place to start looking into using the NXSac's in place of NXS's as reagents.
They surely can replace the latter in any reaction, and only differ in the extent of how well they can substitute the respective N-halosuccinimides.
But yes, I know, examples of the usage of NXSac's are relatively scarce to find, despite the relatively ease of making these N-halosaccharines.
I guess we need a brave amateur chemists who tries that stuff for reactions where N-halosuccinimides are to be used normally... 
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mr_bovinejony
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Yeah you sent that paper, but after finding saccharin for very cheap I decided to look more into it. Even if they didn't work as well, the cost is so
small compared to succinimide that I could use a 20 molar excess and not even care  ill probably have to prepare some since the paper i linked above suggest its regioselective almost on par with nbs in Acetonitrile.
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karlos³
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I would simply try to use NBSac for a simple reaction that is well known to be working with NBS.
Maybe brominate a ketone with it, use 10%mol of TsOH as catalyst, in acetonitrile, just as usual and check how well that works?
Or use it in the hofmann rearrangement, or for the aromatic bromination, whatever substrate is least valuable to you.
Yeah well if you use a 20x excess you will of course get a different outcome, dibromination is probably the least of your worries in that case
If you ask me, I believe that, depending on the reaction its used for, it won't be disappointing.
Maybe prolong the reaction time somewhat, or check ideally with TLC how fast it progresses, to compare how fast the same reaction works opposed to
NBS.
As for the problem Boffis describes, I don't had any issues with NBS either.
Often you can just precipitate your product with water as they are mostly insoluble in it, unlike succinimide, and thus are able to easily isolate it.
But for the free acidic saccharin, this seems to be more of an issue with its low solubility... however this allows for an easy recovery for reuse on
the other hand.
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valeg96
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Quote: Originally posted by mr_bovinejony  | I have heard about
It all seems just fine, but I have yet to come across any kind of "non-professional" reports of its use and the practicality of its halogenating
properties. Has anyone used these halosaccharins with great success where a halosuccinimide or even just a halogen would be used?
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There is a seemingly simple way of halogenating arenes with iodosaccharin, made by reacting the silver salt of saccharin with I2 in acetone. Attached
you find an article I found many years ago but never bothered to try, as I don't have any saccharin. Preparation of aryl iodides is way more
interesting than bromides or chlorides, as there are not as many routes.
Also, you have not come across non-academic reports because
Iodination reactions are the kind of chemistry you use to make fine chemicals and specialty products, so no reputable company with a working,
efficient productive process will tell you how it's carried out. You can probably find patents, if you look enough, but they usually aren't very
user-friendly.
On an industrial setting it's much cheaper to use the raw elements, rather than complex halogenating agents. Organic fluorides are made with HF and
fluorine, not with all the super-specialty fluorinating agents you see reported in articles. Only a small minority of the things you see and do in a
lab can be trasferred to an industrial setting. For example, Grignard reactions are extremely hard to replicate industrially, and much more dangerous.
Attachment: iodosaccarina Dolenc 2000.pdf (55kB)
This file has been downloaded 276 times
[Edited on 14-12-2020 by valeg96]
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mr_bovinejony
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I had planned on trying the finkelstein reaction to make some iodine compound, but I do have some silver salt i don't need if that doesn't work out.
But like you said I have rarely seen iodine used except for special chemicals that require the iodine group, at least with aromatic halogen compounds
they are well documented with chlorine and bromine
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karlos³
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Well you can apparently make 2C-I with NISac which you can't, for whatever reason, with NIS.
So it is definitely of much use for us.
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AvBaeyer
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Perhaps you will find these instructive. Both deal with halosaccharins.
AvB
Attachment: N-Bromosaccharin Review kim2012.pdf (95kB)
This file has been downloaded 295 times
Attachment: Use of N-Halo Compounds in Synthesis Review veisi2011.pdf (3.8MB)
This file has been downloaded 275 times
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mr_bovinejony
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I got my saccharin today so I ran some trials. Heres the specifics
3 beakers each with 10.25 g of sodium saccharin, 2.6 g of sodium carbonate, and 200 mls of water
NaCl - 3 grams
NaBr - 5 grams
KI - 8.5 grams
3 beakers of 31 grams of oxone dissolved in 30 mls of water were prepared.
No ice bath needed like the paper suggest. And as for stirring for 24 hours, thats probably bullshit as well. Unless something else formed that
precipitates quickly, the product fell out right away.
The first beaker containing chlorine was the most calm. No crazy precipitate formed and stirring was easy. There was some small amount of foaming but
it was controlled with slow additions of the oxone.
The second beaker with bromine was a little bit tougher. Some foam collected on top and the orange color stayed around and is still around. The
familiar burning sensation from bromine is in my nostrils.
The last beaker with iodine I fear has failed. As soon as the first bit of oxone was added the whole thing turned to grape kool-aid. There is no white
precipitate of product visible beyond the precipitate of iodine. I guess this was to be expected tho. I might try to work it up with sublimation to
remove the iodine and then a shit ton of water washing, but ill most likely be reacting the solution with sodium thiosulfate and my drain.
I'll get some yields for you people asap. This was a fun little experiment, I have a few aromatics I want to react them with for some regioselective
reasons, namely benzamide and 3 bromo anisole.
There also exists a nitro saccharin I want to make, but thats not a priority right now. It would be nice though to have a nitrating compounds without
wasting sulfuric and nitric acid.
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valeg96
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I haven't read all the articles shared in this thread, but what I posted about iodosaccharin definitely wasn't "saccharin sodium+KI+substrate". There
is a reason why they go through the silver salt and then convert it to the iodine compound.
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mr_bovinejony
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Yeah the iodine compound was just a fun exercise since I had never made elemental iodine before.
Here's the yields. Well, yield singular
4.7 grams of chloro sacc
The bromo sacc had made particles of way too small a size and I didn't feel like fucking with celite or a long filtration. But I estimate there was
around 3 grams after it had all settled to the bottom. More experiments will be done to find a recrystalization solvent so I can get filterable
crystals. Chlorine sucks anyway and I much prefer bromine compounds.
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