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Corrosive Joeseph
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https://www.youtube.com/c/ExtractionsIre/videos
/CJ
Being well adjusted to a sick society is no measure of one's mental health
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draculic acid69
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Quote: Originally posted by not_important  | p-dichlorobenzene + AlCl3 gives mostly a mix of the dichlorobenzene isomers, the chlorines seem happy to hop about on the ring but don't like to jump
rings. Careful fractionation of the mix might be able to remove benzene, I've not tried that as several reports stated no ring jumping for Cl although
Br has been stated to ring jump.
If the mixed dichlorobenzene isomers are cooled so the much of the para isomer freezes out, the ramaing mix is a useful not-too-reactive solvent.
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I know this is an old thread but I'm interested in this mention of
chlorine jumping around on the ring and turning 1,4 dcb into
1,2&1,3dcb is great news if true. If anyone has any experience or
information about the moving around of halogens on the ring please
enlighten me.
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MrDoctor
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I am curious, has anyone ever actually succeeded in using HCl bubbled into toluene with Al+AlCl3?
I have heard 2 claims, firstly that this yields benzene, among other things, and the other, that this yields AlCl3, even if not in quantities alone
that justify the reaction as a low temperature route to produce AlCl3.
Frankly it seems too good to be true, that you can have nice cheap benzene AND you end up with more AlCl3 than you started with.
Where i live, benzoate is getting less obtainable for cheap, and more and more industrial chemicals are being pulled from the shelves or their sale is
being restricted to businesses/business entities only. a little while ago i had to jump through several hoops just to obtain 50 grams of crystal
violet for running a gram stain.
Otherwise the route i had thought of taking would be catalytic oxidation of toluene in a heated quartz tube with vanadium and other metal oxide
catalyst. One paper of interest was "Oxidation of Toluene to Benzoic Acid Catalyzed by Modified Vanadium Oxide" Iraqi Journal of Chemical and
Petroleum Engineering, Vol.15 No.1 (March 2014) 73- 77
playing around with different mixtures of vanadium, molybdenum and cobalt seems to be able to shift the conversion in favor of benzene sometimes, as
does changing the reaction temperature and steam content. Other papers have described greater benzene selectivity, but they require unreasonably high
pressure, or unobtainable catalysts, like uranium.
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Mateo_swe
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The sodium benzoate and NaOH method works very good and is the only method i have tried.
For me its enough to make the small amount of benzene i might need.
As benzene is not the healthiest of compounds its usually not used in more modern preparations.
So if you need just a smaller amount, i would do the benzoate/NaOH method.
And 1kg of sodium benzoate on ebay is about 22 Euros, not very expensive.
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Texium
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I use benzene regularly in my research, as the solvent for a radical bromination with NBS/benzoyl peroxide. It still shines in that application, since
other common solvents are reactive to radicals.
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Keras
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| Quote: Originally posted by Texium | | I use benzene regularly in my research, as the solvent for a radical bromination with NBS/benzoyl peroxide. It still shines in that application, since
other common solvents are reactive to radicals. |
Interesting. I have a litre of pure benzene, might use it to try anti-markovnikov additions to double bonds. Anything handier than NBS and benzoyl
peroxide? Would HBr with peroxyacetic acid work?
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MrDoctor
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| Quote: Originally posted by MrDoctor | I am curious, has anyone ever actually succeeded in using HCl bubbled into toluene with Al+AlCl3?
I have heard 2 claims, firstly that this yields benzene, among other things, and the other, that this yields AlCl3, even if not in quantities alone
that justify the reaction as a low temperature route to produce AlCl3.
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I dont recall if i originally read someone in this thread or elsewhere had poor results or not, or wasted some days and dry HCl with no result, but i
have found something useful. There exists a complex between AlCl3 and benzene refered to as R-AlCl3 or Radzivanovskii-AlCl3, produced by bubbling dry
HCl into benzene containing aluminum. the R-AlCl3 forms a sort of brown scum on the metal and functions as a friedel-crafts catalyst. I have not heard
though if the benzene can be seperated since it does form a complex, which is something i want to try in the future.
Anyway, if one was to bubble HCl into toluene containing benzene already, it would produce increasing amounts of benzene and AlCl3 as i saw once
claimed. The fact it was hit or miss, between people who attempted it, might have to do with whether or not they began with some AlCl3 catalyst to
begin with. Although, they have it backwards, since its the benzene the AlCl3 turns the toluene into, that lets the reaction progress, and it might
also be that not very much can be produced with heavy dilution, so one wastes an enormous amount of HCl trying to increase the miniscule amount of
AlCl3 present, as well as the actual solubility of HCl too in solution, which would be poor. lastly, the composition and physical surface of the
aluminum seems to matter too.
I think if one was to first produce a large amount of catalyst just in benzene, then the reaction should play out as claimed/theorized once toluene is
added and heated. doing both together might prove unfavorable though
I think it would take many cycles of heating, and gassing, to get a decent build up of the necessary benzene or AlCl3 if you only had a small amount
of just 1 to start with.
Attachment: Chem_Abs_45_Friedel_Crafts_with_Al_catalyst.pdf (412kB)
This file has been downloaded 56 times
[Edited on 6-9-2024 by MrDoctor]
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