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Nicodem
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| Quote: | Originally posted by tupence_hapeny
For instance, how does chloroform cope with benzoyl peroxide? Alternatively, wouldn't trichloroethylene be just as effective? Particularly if, as
would appear likely, it was converted to the tetrachlor in situ? |
No, trichloethylene would be a bad choice. Besides nobody sane of mind would use CCl4 or any other solvent for a preparative benzylic
chlorination of toluene with TCCA when the reaction proceeds just as well with excess toluene as solvent. Why would you want to add something as nasty
as CCl4 or just any other things that would just complicate the fractionation in the reaction workup?
| Quote: | Anyhow, this is my opinion, if someone wants to direct me to a 80+% conversion & yield, 1 step approach, I would obviously prefer that - then
again, so would industry |
Benzyl chloride can be consistently oxidized to benzaldehyde with >80% yield. Where did you see claims to otherwise?
| Quote: | | PS the catalyst for the reaction is Benzoyl peroxide, I do not suggest using the H2SO4 or FeCL2, however - we have a problem with the solvent only.
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Benzoyl peroxide is not a catalyst in the above mentioned chlorination. It is only a radical initiator required to induce a change in the chlorination
mechanism. You can use sun light or a mercury lamp instead. H2SO4 and FeCl3 have no place in this preparation since they would cause the consumption
of TCCA by ring chlorination of toluene before any benzyl chloride would form. It would also be a bitch to separate o- and p-chlorotoluene from benzyl
chloride, so make sure there are no such acids present in the reaction mixture.
| Quote: | | BTW, this would appear to, at least, partially validate your proposal that TCCA could be useful for the preparation of acyl chlorides, especially
given that this route is essentially the same as another which uses the same system, albeit with sulfuryl chloride (but still toluene & benzoyl
peroxide) to prepare benzyl chloride. This would suggest that TCCA is a fairly useful chlorinating agent, of the same category as sulfuryl chloride,
thionyl chloride, etc. |
What are you talking about? You can not use TCCA per se for chlorination of carboxylic acids to acyl chlorides. It can only do so in the presence of
triphenyl phosphine and similar "aprotic" reducents, but why would anybody want to use TCCA/Ph3P for that when POCl3, SOCl2, oxalyl chloride and such
would be way more practical (not to mention cyanuric chloride that Sauron keeps promoting so annoyingly at any opportunity he gets). You can use TCCA
instead other chlorinating oxidants like sulfuryl chloride or Cl2 in many cases, but certainly not instead thionyl chloride or POCl3. Have you
confused something again?
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Sauron
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I think tup does not know the difference between TCCA and TCT (CC), that's all. Also he does not know the difference between a "proposal" for a
carboxylic acid chlorination method and a solidly documented literature method for the last 30 years.
@Nicodem, why do you find my "promotion" of TCT annoying? I find it versatile and useful, it is inexpensive and easily handled, and readily available
except in EU. It can be used to prepare valuable reagents otherwise difficult to access by purchase. Like oxalyl chloride and acetyl chloride, and
acetic anhydride by extension; propionyl chloride, etc. By comparison many of the reagents you propose above are simply outlawed in many places
without a special government dispensation. Thionyl chloride, phosphoryl chloride both CWC listed. In this country I'd have to kiss the ass of the MOD
for a permit to import those. And that would be unlikely to be granted. A large corporation or a government university MIGHT get such a permit. No
permit reqd for TCT. TCT can do many of the dehydration and condensation reactions of POCl3. It can be used to prepare alkyl chlorides, bromides and
iodides as well as acyl chlorides. It converts ketoximes to amides and aldoximes to nitriles (Beckmann) under very mild conditions.
So I think as long as I keep finding new uses for TCT/CC not yet discussed on this forum or underdiscussed, I will just go on "annoying" you. You act
as if you think I get a royalty or commission on every Kg TCT sold, instead of just trying to post useful and practical information for the members.
---------
For a change of pace here are not one but two preparations of benzaldehyde using TCCA (sorry, @Nicodem, not TCT) in moderate yield
1. slight excess benzyl ethyl ether + TCCA -> benzaldehyde 53% + ethyl benzoate <5%
Stirred 15 hrs @ 3 C and in presence of an excess of water.
2. Benzyl alcohol + TCCA -> benzaldehyde 53%
3 C, stir, time not given. Excess of water present.
Thanks for the correction @Nicodem - misreading on my part.
The benzyl alcohol route is the more interesting as the benzyl ethyl ether would be less common/more expensive and would be prepared from the alcohol
most likely anyway.
[Edited on 21-4-2007 by Sauron]
Attachment: tl1968[1].pdf (89kB)
This file has been downloaded 2345 times
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Nicodem
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| Quote: | Originally posted by Sauron
@Nicodem, why do you find my "promotion" of TCT annoying?
...
You act as if you think I get a royalty or commission on every Kg TCT sold, instead of just trying to post useful and practical information for the
members. |
You said it! It does not matter if it is not true. What matters is that you persistently try to make it look this way. Obviously, cyanuric chloride is
a very useful reagent, not just for making herbicides, but especially for members here who want to make acid chlorides and have no access to SOCl2 or
POCl3. I certainly do not mind reading as much literature about it as possible. But do you just have to exaggerate so much in its promotion? Do I have
to note that lately you have been promoting it, for example, even for things like preparation of benzyl chloride from benzyl alcohol when something as
OTC as hydrochloric acid suffices? If that can not be considered an annoying exaggeration, then I just don't know what it is. I can understand
Tupence's propositions in making simple preparations as complex as they can get since he obviously knows practically nothing about organic chemistry
and even less so about practical chemistry, but you often like to do the same.
| Quote: | For a change of pace here are not one but two preparations of benzaldehyde using TCCA (sorry, @Nicodem, not TCT) in moderate yield
1. slight excess Phenetole (phenyl ethyl ether) + TCCA -> benzaldehyde 53% + ethyl formate <5% |
It is benzyl ethyl ether (PhCH2OEt) and not phenethole. And the side product is ethyl benzoate and not ethyl formate.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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tupence_hapeny
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@Nicodem,
Benzyl Chloride most assuredly can be oxidised to benzaldehyde in over 80% yield, I agree, that was not my point. My point was that Toluene can not be
oxidised directly to benzaldehyde in anything like that yield, thus the suggested two-step process.
http://pubs.acs.org/cgi-bin/abstract.cgi/iecred/1990/29/i07/...
@Sauron,
I have not been able, until I carried out my own research (which has taken more time than I really have to give) to find all that many references to
what you state is a known process? This is fine, however, as the simple fact is, mild reactions with available reagents appeal to me (and to many
others) and I don't mind doing my own research. I became interested in the idea, basically because of your continued references to the same, do you
have any further details or references?
However, given that I have only just managed to access some recent literature, which details the resurgent interest in this reagent (also
1,3-dihalo-5,5-dimethylhydantoin) - I have only just managed to find the references which were lacking in your previous posts regarding this
procedure. I feel sure that others here, beside myself, would be interested in such procedures - especially if specific details were forthcoming?
That said (also note that I edited my previous post regarding the differences between cyanuric chloride and trichloroisocyanuric acid), I have begun
to encounter a number of papers, detailing the uses of this reagent. Nicodem is partially correct, quite a few proceed only in the presence of
triphenyl phosphite(?), although it appears that others do not require the same.
I am not here to piss in anyones pocket (please DO trust me on that - I have NO reason to be overly fond of either Sauron or Nicodem), quite frankly,
I started researching the topic because it appeared somewhat farfetched and improbable. I am however, only interested in the application of the same
and the chemistry, if it works it will be a fucking great day for me and others - who quite frankly, haven't a snowballs chance in hell of being
allowed to buy PCl3/PCl5/POCl3 either now or at any time before hell freezes over.
Lets keep to the science, I ain't interested in your egos
PS Nicodem, I thought you would have read the Electrochemica Acta article? Are you suggesting that the author really utilized a solvent when excess
toluene would have done just as well? I find that hard to believe, which is unusual, as you are normally very informative and honest, albeit somewhat
spiteful at times?
We are all the sum of our experiences, and our reactions to the same
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Nicodem
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| Quote: | Originally posted by tupence_hapeny
PS Nicodem, I thought you would have read the Electrochemica Acta article? Are you suggesting that the author really utilized a solvent when excess
toluene would have done just as well? I find that hard to believe, which is unusual, as you are normally very informative and honest, albeit somewhat
spiteful at times? |
What are you talking again? I was replying to your discussion about CCl4 as a solvent in the benzylic chlorination of toluene by Juenge et al.
PS: Try to UTFSE about TCCA. You will find many papers and relevant threads.
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Sauron
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@tup, I have POSTED quite a few articles here on TCT/CC so UTFSE!
I have not posted any that require triphenylphosphine, which reagent is a pain in the ass to use. It requires scrupulous drying and air-free handling
or it either fails, or oxidizes to triphenyl phosphate in a New York minute.
As the search engine sucks, if you can't find them I will assemble the links and PM the list to you.
Google will reveal a lot of activity with TCT/CC.
TCCA is also quite interesting, but not as stategically so IMO as TCT. TCCA is much more OTC.
Nothing to do with egos. I liked your posted articles in this thread, and was sorry to have had to poke a hole in that one, but there it was to be
poked. So maybe you should read your chosen articles before putting them up, eh? I know the temptation is great to post first and study later when
something looks promising. But that can come back to bite you.
Lots of people are confused by distinction between TCT and TCCA so that is nothing to be concerned about. They are quite similar and both derive from
cyanuric acid. But they have very different chemistries, one being a N-chloro compound and the other being essentially an acid chloride.
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tupence_hapeny
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Nicodem,
| Quote: | | What are you talking again? I was replying to your discussion about CCl4 as a solvent in the benzylic chlorination of toluene by Juenge et al.
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I presume that this statement attempts to answer the question that I asked on the previous page, for your benefit therefore, I will provide a direct
quote of the same, where the question was asked:
| Quote: | | I ask this last question as I have access to gallons of trichlor for stuff all (electrical cleaning solvent) and would really like to know if it would
be able to be used instead of chloroform in the electrolytic chlorination procedure |
For those that have not read the article that was cited, it refered to a 2-phase electrolytic chlorination of toluene, which was in chloroform (and
stirred at 40rpm) while the top (aqueous phase) contained deionised water and NaCl and two (platinum) electrodes and was not stirred.
I realise that I may have confused you, for which I apologise, however, as this is (for mine) the simplest, high yielding method of converting toluene
to benzyl chloride (I don't care how OTC HCl is, NaCl is even more so). Now I reiterate the original question, is it possible to use trichloroethylene
instead of chloroform?
However, and just so that I do not appear to utterly spiteful and horrid, here is an article which supports your statement re.PPh3 being necessary for
some such reactions with acids to acyl chlorides.
[Edited on 21-4-2007 by tupence_hapeny]
Attachment: Mild One-Pot conversion of Acid to Acid Chloride PPh3 & TCCA (2005) 46 Tet Let 5945.pdf (103kB)
This file has been downloaded 10502 times
We are all the sum of our experiences, and our reactions to the same
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Organikum
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| Quote: | Originally posted by Sauron
Both look interesting.
44% yield is not so impressive, but might be useful for the chemically challenged who cannot obtain TCT.
TCCA does seem to be ubiquitous.
TCT/DMF and benzyl alcohol ->benzyl chloride 100%.
Anyone making BzCl is going to need a good hood.
Hmmm. You forgot to mention a wee detail. Your 44% chlorination of toluene w/TCCA ONLY RUNS IN CCl4. In absence of carbon tetrachloride, TCCA with
either of the two catalysts (FeCl2 or H2SO4) produced ONLY mixed o- and p-chlorotoluenes in modest yields 45-66% and no benzyl chloride.
That takes it right out of the OTC category and dumps it in the UNOBTAINIUM file. CCl4 is no longer available in most countried OTC and is restricted
(by special license only) for academic or industrial users, just like chloroform and Tric, Perc, ethylene dichloride etc. Is this not the case where
you are? It's the bloody environmentalist assholes at work.
Waste of time!
Some nice references in there, re TCCA iand THF -> GBL. Well maybe not so nice. 19% yld, ugh.
[Edited on 21-4-2007 by Sauron] |
Adding TCCA in small chunks to 5-fold excess of almost boiling toluene with a small amount of HCl added under irridation of a 150W halogen lamp
without UV protection produces Benzylchloride in decent yields. The main problem was the separation of the product/toluene from the cyanuric acid
which is IMHO very hard to filter.
Upon addition of alcohol/water + hexamine benzaldehyde is formed in good yields. I think I posted this already.
The HCl is necesssary to initiate the reaction. Without it one can add a lot of TCCA without much going to happen and suddenly when the reaction kicks
in one is confonted with a very unpleasant runaway.
When the reaction does not kick in after the first chunk is added, add more HCl (30% is ok, alternativly one can mix conc. HCl with toluene let this
sit for some hours and separate. Some HCl will be go into in the toluene and use this) DONT ADD MORE TCCA!
The addition of chunks of TCCA to almost boiling toluene with a halogen lamp next is NOT trivial. Using a longer glasstube on the sideneck is strictly
advised. A good condensor is also necessary, a Liebig does not suffice, a spiral does.
The reaction goes quick and smooth, the workup was unpleasant. If somebody has a good method for filtration of precipitated cyanuric acid - tell.
Gravity filtration methods are preferred.
For the used subtrates are cheap and abundant yields are actually not so very important, the procedure is not without dangers though - be careful.
The large excess of toluene prevents most of polychlorination.
Been there done that.
Works.
/ORG
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Nicodem
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Organikum, I think your method produces a lot of ring chlorinated toluene as well. Did you perform any kind of analysis of the product?
Edit: Tupence, my answer about solvents was equally valid for that Indian method. When adapting an experimental procedure to a preparative one you
don't want to make it more complex, dangerous and expensive, you want the opposite. I thought that needed not to be emphasized.
[Edited on by Nicodem]
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tupence_hapeny
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Thanks organikum,
I honestly looked and did not find that in the search engine, shit, I thought I had 'DISCOVERED' something
Honestly though, I was mainly looking to drum up interest in the electrochemical process, I mean now I have limited access to decent journals, I may
be able to contribute something? Anyhow, please have a look at the electrochem article, it appears promising, although I would obviously prefer to use
an OTC solvent.
We are all the sum of our experiences, and our reactions to the same
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Sauron
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@Nicodem, I think it is you who is stretching a point. While I have no doubt that conc HCl can chlorinate benzyl alcohol, I'd like to hear
representative time, temperature and yield details.
Whereas I can tell you that for TCT/DMF those are
15 minutes
ambient temp (stirring only)
100% purified yield (quantitative.)
So if I needed a Kg BzCl I'd choose TCT/DMF
And If I wa a clandustrialist I might favor an economical method to make some much larger quantity.
I have studies the comparative costs of other chlorinating reagents for the conversion of acetic acid to acetyl chloride and TCT always comes out as
cheapest. It is easy to figure why.
TCT three active chlorines Low price
Benzoyl chloride one active chlorine, low price
Phthaloyl chloride two active chlorines high price
The last two are used in 50-100% excess, TCT is used in stoichiometric fashion on basis of active chlorines (2 or 3)
It is possible with effort to make one's own phthaloyl chloride (as I posted) and this levels out cost to about same as benzoyl chloride if certain
assumptions are made and labor cost is ignored.
But TCT still comes out cheaper EVERY time. Also it is applicable to less volatile acid chlorides whose bp's are too close to benzoyl or phthaloyl
chloride to make those possible.
In the end the choice of reagent is a personal/professional one and no one can force anyone to use this or that. I am not selling TCT. I am merely
enthusiastic about it. Allow me my enthusiasms.
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Nicodem
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| Quote: | Originally posted by Nicodem
Organikum, I think your method produces a lot of ring chlorinated toluene as well. Did you perform any kind of analysis of the product?
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Organikum, nevermind, I reconsidered. The small amount of water introduced with hydrochloric acid is able to catalyze the ring chlorination to some
extent, but on second thought I realized that the vapors of toluene would carry most moisture with the azeotrope out of the reaction mixture before it
would do much harm. And I also only now noticed that you actually found a way to avoid this problem by partitioning toluene with conc. HCl as an
alternative to adding conc. HCl directly to the reaction mixture.
PS: Cyanuric acid filters just nice using vacuum filtration. Maybe you use too fine filter paper? Alternatively you could try adding just enough water
in ethanol (1.5ml H2O per 10g of TCCA used) to form the more crystalline cyanuric acid dihydrate which is even much easier to filter.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Sauron
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Yep. benzal diacetate helped in Org.Syn as well.
But thanks for the comment.
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Hilski
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| Quote: | | My point was that Toluene can not be oxidised directly to benzaldehyde in anything like that yield |
Um, yes.....it can.
\"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety. \"
- Benjamin Franklin
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Nicodem
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| Quote: | Originally posted by tupence_hapeny
PS Nicodem, I thought you would have read the Electrochemica Acta article? Are you suggesting that the author really utilized a solvent when excess
toluene would have done just as well? I find that hard to believe, which is unusual, as you are normally very informative and honest, albeit somewhat
spiteful at times? |
You still need to learn the difference between an experimental and a preparative procedure. In a preparative procedure one would not use CHCl3 as
solvent, but just an excess of toluene while in an experimental one it is not advisable to do so.
You do not even need a particularly efficient distillation column for separating benzyl chloride from the unreacted toluene – the boiling points are
well apart.
Anyway, though it is an Indian paper, it is surprisingly well written and might actually be genuine and reproducible. Try it out and report back if
you got any tears from benzyl chloride. 
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Organikum
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| Quote: | Originally posted by Nicodem
| Quote: | Originally posted by tupence_hapeny
PS Nicodem, I thought you would have read the Electrochemica Acta article? Are you suggesting that the author really utilized a solvent when excess
toluene would have done just as well? I find that hard to believe, which is unusual, as you are normally very informative and honest, albeit somewhat
spiteful at times? |
You still need to learn the difference between an experimental and a preparative procedure. In a preparative procedure one would not use CHCl3 as
solvent, but just an excess of toluene while in an experimental one it is not advisable to do so.
You do not even need a particularly efficient distillation column for separating benzyl chloride from the unreacted toluene – the boiling points
are well apart.
Anyway, though it is an Indian paper, it is surprisingly well written and might actually be genuine and reproducible. Try it out and report back if
you got any tears from benzyl chloride. |
I am not so sure about this. Besides the the funny way they create chlorine in situ this article says that wet toluene can be
monochlorinated at the sidechain at rather low temperatures with only small amounts of ringchlorinated inpurities and that in excellent yields. Either
this is facilated by the cosolvent - chloroform - or it is utter bullshit for being in contradiction to the most basic literature of organic
chemistry, Vogel, Gattermann and who not else, who say that HIGH temperatures facilate sidechainchlorination, low temperature ringchlorination.
Also I thought that further chlorination of the sidechain is only to prevent by a large excess of toluene, how comes that this stops at the BzCl here.
It´s either the chloroform or it is just another indian bullshit.
Not to speak of the nice task to stir one layer without disturbing the boundaries of the two layers + running a electrolysis in the other layer. Now
thats not trivial one might believe.
Or did I get something wrong again?
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Sauron
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Maybe they added some curry as a PTC.
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tupence_hapeny
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Tally ho,
ummmm, I have to go elsewhere for the next month or so (family issues), I will attempt this procedure whilst at the alternative venue (using
trichloroethylene and another run with excess toluene). The bitch is going to be the anode/cathode materials (not having a surplus of Pt foil - I will try with stainless steel and carbon/graphite).
It is going to be a BITCH to build a mag-stirrer which is controllable to the point of doing just 40rpm - but, providing I can do so - I intend to
give this a shot, as it is quite possibly the easiest route I have seen (providing the fucking thing is reproducible).
BTW, I did not notice where the bloody thing was written - are they really that dodgy?
tup
PS I hope my password will work when I get back
PPS @ Sauron, what curry would you recommend? IMHO a korma or rogan josh would be preferable - seems that they would be easier to stir - although a
good spicy curry would be a valuable adjunct in hiding the fumes of the benzyl chloride
@ Nicodem, thank you for your assistance and words of wisdom
& @ Organikum, what can I say - one just has to trust refereed journals sometimes - I know it looks odd, but so does my recent find where H2 is
generated in situ (in reductive amination via Al powder with Pt/C).
At everyone, as I am somewhat amateurish at the hands on aspect of this stuff, could someone else try this shit? I mean, if I fail (and that is only
too likely) that is hardly representative of whether or not the reaction works in the hands of someone who knows what they are doing, is it?
We are all the sum of our experiences, and our reactions to the same
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Nicodem
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| Quote: | Originally posted by Organikum
I am not so sure about this. Besides the the funny way they create chlorine in situ this article says that wet toluene can be monochlorinated at the
sidechain at rather low temperatures with only small amounts of ringchlorinated inpurities and that in excellent yields. Either this is facilated by
the cosolvent - chloroform - or it is utter bullshit for being in contradiction to the most basic literature of organic chemistry, Vogel, Gattermann
and who not else, who say that HIGH temperatures facilate sidechainchlorination, low temperature ringchlorination.
Also I thought that further chlorination of the sidechain is only to prevent by a large excess of toluene, how comes that this stops at the BzCl here.
It´s either the chloroform or it is just another indian bullshit.
Not to speak of the nice task to stir one layer without disturbing the boundaries of the two layers + running a electrolysis in the other layer. Now
thats not trivial one might believe.
Or did I get something wrong again? |
Your doubts are reasonable. There are indeed a couple of suspicious things in that paper. The one that you mention is not even the strangest one since
benzylic positions can be chlorinated at room temperature, just not with chlorine. In the system they use (NaCl/H2SO4) there forms not only chlorine,
but also appreciable amounts of Cl2O which is able to chlorinate toluene to benzyl chloride even at room temperature in the slightest presence of a
radical initiation (light) or heat. However, where there is Cl2O and water together there are also present highly electrophilic species that
chlorinate toluene by electrophilic substitution so their >90% benzylic selectivity is extremely suspicious.
I don't think chloroform has any role in the mechanism. If that would be the case the authors would not miss the opportunity to describe its
importance for the outcome as that would make their paper look better. It is just a standard inert solvent used only so that their method could appear
as having prospects for generality in benzylic chlorination. Besides this way they can claim 85% conversion even though the current efficiency is
lower. If describing an experiment with excess toluene as solvent they could not note the conversion which is very important for the experimental of
the paper.
Their mechanistic proposition sucks in that it smells of the ancient "nascent gas" theory that was debunked already several decades ago.
Stirring without getting the organic phase over the electrodes is in my opinion not that important in a preparative approach where the current density
on the electrode surface needs not to be constant. I think one can just stir normaly provided that the electrode surfaces are high enough to
compensate for the drops of the non-conducting organic phase that sticks to the surface (provided also that the electrodes are made of an inert
material).
| Quote: | Originally posted by tupence_hapeny
I will attempt this procedure whilst at the alternative venue (using trichloroethylene and another run with excess toluene). The bitch is going to be
the anode/cathode materials (not having a surplus of Pt foil - I will try with stainless steel and carbon/graphite). |
Didn't I already told you that trichloroethylene is a bad idea? Though it is quite an inert alkene due to the inductive effects of the chlorines, it
is nevertheless an alkene. Benzylic chlorinations proceed by a radical mechanism so you certainly don't want to add anything into the reaction
mixture that quenches radicals.
In this case stainless steel does not work for the anode.
| Quote: | | At everyone, as I am somewhat amateurish at the hands on aspect of this stuff, could someone else try this shit? |
There are other simpler and full proof methods to obtain benzyl chloride so I'm afraid it is up to you to check the validity of this one.
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IPN
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Finally got some TCCA to do some chlorinations with and as I inspected the product it had some blue specs in it (came as 200g pucks). Checking the
MSDS revealed that it contains only 92% TCCA, rest being 4% CuSO4 and 4% Al2(SO4)3.
Any ideas on how to purify it? Recrystallization perhaps? Or do I even need to bother trying to purify it?
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Rosco Bodine
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Sounds like an algaecide there for the copper and
a flocculent for the aluminum sulfates , which will
precipitate as hydroxide when water pH is cycled basic , dragging any particulates from the water with it
by " sliming them " and then getting filtered out . Under acid pH reaction conditions , both should be pretty inert .
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Hilski
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Man, oxidation with Mn salts is so much easier and reproducible that I can't think of any reasons to go the BzCl route.
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to obtain a little temporary safety
deserve neither liberty nor safety. \"
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Sauron
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I'd try finding the TCCA without the inorganic additives.
Otherwise, just find a solvent that dissolves the TCCA readily and does not touch the ionic solids, filter them off, and recover the TCCA.
It's a nuisance, though.
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Nicodem
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| Quote: | Originally posted by IPN
Finally got some TCCA to do some chlorinations with and as I inspected the product it had some blue specs in it (came as 200g pucks). Checking the
MSDS revealed that it contains only 92% TCCA, rest being 4% CuSO4 and 4% Al2(SO4)3.
Any ideas on how to purify it? Recrystallization perhaps? Or do I even need to bother trying to purify it? |
You could dissolve it in ethyl acetate, filter and evaporate. Do not use acetone since CuSO4 and Al2(SO4)3 might catalyze its oxidation with TCCA to
chloroacetone due to their acidity!
Alternatively you could ground it very finely and wash the inorganics with water and let it dry. This will never completely remove them, but will
remove most of it. Besides this, much of TCCA will decompose to dichloroisocyanuric acid by hydrolysis to HClO unless you somehow manage to dry it
very quick.
PS1: But why don't you just buy TCCA without additives? Surely it must be available. I never saw it being sold with additives anyway.
PS2: Hilski is right about it. Going trough benzyl chloride is one of the least sensible routes from toluene to benzaldehyde. But if benzyl chloride
is what you need, then chlorination of toluene with TCCA is one of the most sensible routes. Not as sensible as benzyl alcohol with HCl, but toluene
at least is as cheap and available as it can get and the same is true about TCCA.
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IPN
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Thanks for the input.
Unfortunately the company which sold me the TCCA said that because of lack of sales with the non-additive version it was discontinued. I could get it
from sigma-aldrich in pure form but the price is quite high.
I'll try purifying with ethyl acetate to get some purer product. I do need some benzyl chloride but as Hilski said it's much easier to use Mn salts to
oxidize toluene if one needs benzaldehyde.
Main reason to get the TCCA was to make chlorobenzene in large amounts to experiment with the derivatives of 2,4-dinitrochlorobenzene.
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