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Author: Subject: CCl4 and CHCl3 from CH2Cl2
Sauron
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[*] posted on 23-2-2010 at 05:22


That should come as no surprise to anyone who has spent much time in Wiley's journals. I have complained about this more than once.

I do not recall where I found a citation to this paper nor whether I fished it out of Wiley or from th Emil Fischer collection of Annalen I have on DVD.

Some may recall I posted that collection in References last year.





[Edited on 23-2-2010 by Sauron]




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[*] posted on 23-2-2010 at 05:27


No, I avoid rabid things such as curs, coons, skunks and you.

You in effect accused me of lyimg about a reference when in fact that reference was real and posted in German and in translation on this very forum.

Thus you make yourself appear an ass.

You proceeded with an ad hominem attack on me, and then when I throw your gauntlet back in your face you wax aggrieved.

Utterly contemptible poltroon! Next time do your homework.

[Edited on 23-2-2010 by Sauron]




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[*] posted on 23-2-2010 at 07:59


this thread was about a chemical I believe, well it was once, long ago, perhaps some of you may remember, it whispers to me in the evening breeze..............quietly............CCl3............CCl4.

Anyway there was an allusion to trichloroacetic acid, actually more of a direct referral to it than an allusion, anyway, i have some but no CCl4, does it readily react with benzoyl chloride to form the carbon tet of old fables whispered in the wind?




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[*] posted on 23-2-2010 at 09:15


Chlorination of trichloroacetic acid to trichloroacetyl chloride by means of benzoyl cghloride (not benzyl chloride) was reported by HC Brown in a JACS paper I have posted more than once, to give 10-20% CCl4 along with the acid chloride.

A review on chloral chemistry states that chlorination os TCAA wiyj Cl2 under UV gives complete conversion to CCl4 along with some phosgene.

There are better ways to make CCl4. Starting from GAA or EtOH to get to TCAA is wasteful of chlorine and tedious.

All of this has been discussed in other threads, which see. The topic of THIS thread is supposed to be getting to CCl4 from DCM via CHCl3.

[Edited on 23-2-2010 by Sauron]




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[*] posted on 23-2-2010 at 09:18


Welcome back, Sauron....please try not to get sucked into petty bickering? The SbCl5 as chlorination catalyst looks interesting and doable. Also not that hard to obtain OTC....I collected several Kilos of SbCl3-SbCl5 from the H2O2+HCl treatment of the residue left from making SnCl2 by boiling 95-5 Sn-Sb solder in muriatic acid (HCl+H2O). The antimony chlorides seem stable enough to obtain by dehydration of aqueous solutions. :D

Tetrachloroethylene is easy as dirt to get in USA as brake cleaner or dry cleaning solvent...seems worth a try as well.


[Edited on 2-23-2010 by Eclectic]
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[*] posted on 23-2-2010 at 09:32


SbCl3 is quite cheap and I have no problem obtaining it. Wheel weights (OTC) are Db and are used by bullet casters to harden lead. Preparing SbCl3 or SbCl5 from the elements is easy, see Brauer.



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[*] posted on 23-2-2010 at 18:36


Quote: Originally posted by len1  
Interesting, when you do a search on Annalen (anyone can do this even without access) for Hofmann, this article doesnt come up. Yet when you go to the contents pages it is there, without attribution to an author, obviously you cant trust Wiley's search engine.

Sauron have you been bitten? Though not recently, its getting worse.


The author of said article is no pseudonym, it is indeed A W Hofmann of Hofmann rearrangement fame. It is clearly labelled part 3. The previous article in Wiley is labelled part 2, and the article before that carries Hofmanns name - and is part 1.

If one searches for Hofmann, among the 200 or so hits you get the first part of this article with a completely different subject. The other parts are listed as separate articles, but with no author.

If one reads what I wrote there is no accusation of lying about the article - I wouldnt have posted my request if I thought there was nothing to it, at the time I thought the author could have been mistaken, or the publication, hardly amounts to lying. Now that you mention it, there is a subsequent accusation about lying in 5000+ posts about a multitude of things the poster was about to do, without any of it subsequently materializing.
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[*] posted on 23-2-2010 at 18:53


I'm through with you, liar, and this yj\\thread has returned to chemistry not your spleen.

[Edited on 24-2-2010 by Sauron]




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[*] posted on 24-2-2010 at 16:04


Quote: Originally posted by Sauron  

There are better ways to make CCl4. Starting from GAA or EtOH to get to TCAA is wasteful of chlorine and tedious.



Yes, however I have some 1500g of TCAA, that i have not even glanced at since acquired some two years back, i guess though it would only make around 500ml CCl4, at best with all things considered.

Quote: Originally posted by Sauron  


All of this has been discussed in other threads, which see. The topic of THIS thread is supposed to be getting to CCl4 from DCM via CHCl3.


Touche fine chap!

I however i repel your parry with a deft flourish of my foil (btw that's all my fencing jargon thoroughly exhausted.)

If i used TCCA to further chlorinate my TCAA and published the results i would have to be up for an acronym award of some kind, especially if i littered the paper with so many TCCA's and TCAA's that one would need some sort of OCD to decipher it.



[Edited on 25-2-2010 by Panache]




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[*] posted on 24-2-2010 at 20:37


You could avoid the acronym muddle by using KMnO4 rather than TCCA as reagent to generate Cl2 from conc HCl(aq).

But I agree that if you have a Kg and a half of trichloroacetic acid that you have no other use for, and you have a need for CCl4 and no good way to buy same, then UV chlorination of the acis makes sense.

What happens is that Cl3CC(=O)Cl forms and fragments into the Cl3C radical plus CO, and other shards. Are you prepared to deal woth CO and some phosgene?

The Cl3C radical reacts with Cl radicals present to form CCl4.

There is a monograph on chloral in Chem Rev I posted a few years ago that details this. Chloral is easier to prepare than TCAA for those who don't have 1500 g on hand.

I think if you search on chloral in the ACS SE for Chem Rev you will quickly obtain the citation, and if you availed yourself of the Chem Rev archive from alter then you just need to pull it up.

The forum FSE failed to even find the thread.

Chemistry of chloral
F. I. Luknitskii
Chem. Rev., 1975, 75 (3), pp 259–289
Publication Date: June 1975 ()
DOI: 10.1021/cr60295a001


[Edited on 25-2-2010 by Sauron]




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[*] posted on 24-2-2010 at 22:04


In my opinion the main advantage of proceeding from ethanol rather than GAA is that UV is only used in the final scission
rather than throughout.

As long as we are being OT there is perhaps a better employement for your TCAA

There is a patent to Rhone on production of oxalyl chloride.

Prepare the trichloroacetyl diester of ethylene glycol. The patent teaches use of the acis chloride for the esterification.

UV-percglorinate this

Treat with an amine catalyst and voila, (COCl)2

The trichloroacetyl chloride is revoverable almost entirely.

This patent has been posted before in one of the oxalyl chloride threads.

I post it here for convenience.

The problem now becomes the best way to covert your acid to acyl chloride and I commend the Herbert Brown method, i.e. benzoyl chloride. After all the CCl4 side product is something you want anyway.

A Convenient Preparation of Volatile Acid Chlorides
Herbert C. Brown
J. Am. Chem. Soc., 1938, 60 (6), pp 1325–1328
Publication Date: June 1938 ()
DOI: 10.1021/ja01273a014


Attachment: US4301092.pdf (178kB)
This file has been downloaded 545 times



[Edited on 25-2-2010 by Sauron]




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[*] posted on 25-2-2010 at 03:55


I ran across a patent that described prep of tricgloroacetyl cghloride in high yield by chlorination sans UV over GAC from a variety of starting materials, including acetaldehyde, chloral, acetyl chloride, and dichloroactyl chloride. Both vapor and liquid phase reactions are detailed as well as atmospheric and pressure conditions.

Scission to CCl4 and CHCl3 is nonzero but usually 1% or less. Never more than 10% for the two combined.

Attachment: US5659078.pdf (102kB)
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[*] posted on 25-2-2010 at 04:43


Solo put up a link for "The Chemistry of Chloral" 11-18-09

http://www.sciencemadness.org/talk/viewthread.php?tid=11698&...
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[*] posted on 25-2-2010 at 05:45


@Eclectic

Note that Brown obtained 88% AcCl with 1.5 mols benzoyl chloride per mo; AcOH while for moomo, di and trichloroacetyl chlorudes the best yields were 76, 73 and 56% respectively and with 2 mols benzoyl chloride per mol acid.

The balance for TCAC and to a lesser extent DCAC is a mix of CCl4 and CHCl3 from scission of the C-C bomd of the acyl chlorides.

[Edited on 25-2-2010 by Sauron]




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[*] posted on 25-2-2010 at 21:33


@Panache

I posted this OT stuff about the Rhone process patent simply because I thought you were interested ub ways to exploit TCAA.

If you are not I will desist.

[Edited on 26-2-2010 by Sauron]




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[*] posted on 17-3-2010 at 18:47


The topic of THIS thread reminded me my schooldays and how happy I was one day when I managed to prepare few cc of CHCl3 by heating a mixture of sodium trichloroacetate (a popular herbicide in the past) and powdered NaOH!
A very friendly and green approach, BTW. Highly recommended for those who don't like HCl atmosphere and when everything is covered with rust ;)
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