Nitrous2000
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Anyone have a simple tetrapropylammonium bromide?
Hi folks,
I’ve read the post on the butyl alcohol version but any simple synthesis to the propyl ammonium bromide version?
Can isopropyl alcohol be a starting point?
Thanks folks - I’m over 30 yrs from my chem degrees and I was a P Chem not a cook! 
Doug
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njl
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I doubt the procedure would be very different for propyl alcohol. I also don't think IPA would be a good starting point unless you're willing to go
through an entire process to functionalize the primary carbon.
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UC235
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No, you'd need to start from n-propanol. Conversion to n-propyl bromide should be fairly trivial and preparation of isopropyl bromide and ethyl
bromide found eslewhere on this forum should work well and in high yield.
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Tsjerk
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Tetraisopropyl ammonium bromide would have to go via triisopropyl amine, which is hard to make because of steric hinderance, making a quartenary out
of it would be impossible.
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karlos³
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Tetraisopropylammonium salts are impossible, wikipedia says the following: | Quote: | | Triisopropylamine is notable as being among the most sterically hindered amines currently known. |
So there is no way you can alkylate that even further.
If you even get to that, if you look at the wiki article, you'll discover the preparation of the trialkylamine is even not doable via the normal
routes.
[Edited on 20-2-2021 by karlos³]
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draculic acid69
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How is it made if not thru the normal routes?
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Texium
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Easy google
https://en.m.wikipedia.org/wiki/Triisopropylamine
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clearly_not_atara
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I would suggest looking into the paper which originally recommended tetrapropylammonium over tetrabutylammonium for this application:
https://pubs.rsc.org/en/content/articlelanding/1987/c3/c3987...
Since butanol is usually much cheaper and easier to get than propanol, it is probably helpful to know whether you can get away with tetrabutylammonium
in this case and what the disadvantages would be.
If you cannot buy n-propanol, any preparation of tetrapropylammonium bromide is going to be rather difficult. You can make propionaldehyde by the
pinacol rearrangement of propylene glycol with sulfuric acid, but you will need a few more steps to get tetrapropylammonium.
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Nitrous2000
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Tetrapropyl ammonium bromide
Thanks for the reply. Seems propyl bromide and tripropylamine are a one step with high yields... but am having trouble sourcing these.
One point I should make here is that my choice of agent is based on a paper detailing a static zinc-bromide (as opposed to the traditional flow-type)
battery that uses this as a bromide complexing agent to act as an electrolyte between plates.
Thanks
Doug
[Edited on 24-2-2021 by Nitrous2000]
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