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BromicAcid
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You cannot use the haloform reaction on CH2Cl2, it is a reaction that is specific for methyl ketones. I think the basic premise of it has been
covered in the garage experiments with trichloromethane. Washing the product repeatedly with water might be a way to make a purer product, but in the
process you are going to contaminate a lot of water, halocarbons are not environmentally friendly.
You could start from CH2Cl2 and either bubble chlorine through it with iodine as a catalyst or also as mentioned above let it sit for a long period of
time in contact with a hypohalite with agitation, however I don't have much information on what conditions best promote chlorination through this
kind of situation (Note, this is not the haloform reaction), just that it can occur, the information that I found specifies in dilute
situations and makes no mention of actively trying to make a tetrahalomethane compound from say a di or tri halo methane compound.
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alchemie
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I was refering to reacting CH2Cl2 with Cl2. Not using CH2Cl2 in the haloform reaction(wich is impossible).
Anyway the important thing I wanted to say was that is is possible to separate CHCl3 (or CH2Cl2 or both) from CCl4 just by washing with water, as
therir water solubilities are so different.
Maybe I didn´t explain myself right. Sorry.
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BromicAcid
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I read through your post too quickly, I thought that you wanted to use the haloform reaction on CH2Cl2, you didn't mention trying to use chlorine
gas. But yeah, as discussed before you could use something like tetrachloroethane which is widely available and react it with chlorine and get your
tetrachloromethane or as you said react dichloromethane with chlorine.
Separation by distillation as you said would be difficult w/o fractioning several times. Though there may be chemical treatments, chloroform will
react with solid KOH but carbon tet will not, so distillation from this may be possible.
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Blackout
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TiCl4 + C => CCl4 + Ti
Can this work or it's like the CaCl2 way?
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runlabrun
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A few questions:
CaCO3 + Urea --> CaCN2 + CO2 + 2H2O
at what temperature does this take place?
and -->
CaCN2 + 6HCl --> CaCl2 + CCl4 + 2NH3
this was said to occur at elevated temperatures.... how elevated?
-rlr
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garage chemist
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BromicAcid, you said that CHCl3 reacts with KOH? What products are formed? I never heard of such a reaction before...
I know that simple Alkyl halides are hydrolysed to the corresponding Alcohol, but I also know that compounds with more than one OH- group on one
carbon atom (an example: carbonic acid, H2CO3) are very unstable.
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Mendeleev
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All these syntheses seem to complicated or requiring weird materials (example: TiCl4). I believe, however, that one can purchase carbon tetrachloride
from a dry cleaner or a place that supplies dry cleaners, that's what they use to remove grease.
Trogdor was a man. A dragon man. Or maybe just a dragon. . .
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S.C. Wack
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No, it really is hard to find, cheap at least.
http://www.google.com/search?hl=en&lr=&q=%22carbon+t...
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JohnWW
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CCl4 was formerly used extensively as a commercial dry cleaning fluid, and in reusable fire extinguishers for fires of inflammable liquids, but was
abandoned because of alleged liver toxicity, and also because of its effect on the ozone layer. 1,1,1-trichloroethane is now the liquid of choice in
dry cleaning (also used for thinning correcting fluid), but frankly I doubt that it is significantly less toxic or damaging to the ozone layer than
CCl4. For reusable fire extinguishers, compressed liquid CO2 (which does not affect the ozone layer) or compressed liquid BCF
(bromochlorofluoromethane, which still affects the ozone layer), both of which are gases at ordinary temperatures and pressures, are now used.
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BromicAcid
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| Quote: | CaCO3 + Urea --> CaCN2 + CO2 + 2H2O
at what temperature does this take place? |
Not sure but it's pretty high (~800C ?), I think this is brought up in the preparation of cyanides thread.
| Quote: | CaCN2 + 6HCl --> CaCl2 + CCl4 + 2NH3
this was said to occur at elevated temperatures.... how elevated? |
Again, no clue, earlier in the thread when I referenced this I quoted all the information that I found word for word, it's not much to go on, I
would think that calcium cyanimide, which will react with water at room temperature, would be reactive enough with HCl and volitize off the CCl4
formed at temperatures as low as 100C.
| Quote: | | BromicAcid, you said that CHCl3 reacts with KOH? What products are formed? |
Chlorobutanol for one, there is a whole thread on it, there are a number of other products formed too, potassium formate among them, it depends on
what else is present, water, acetone, or just straight CHCl3, although I don't know exactly what each of these situations will make.
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BromicAcid
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My procedure today. 260 ml 10% NaOCl [.377 mol] was put into a 500 ml reagent bottle with 24/40 glass stopper. To this was added 5.5 ml acetone
[.125 mol] and the reaction mixture stoppered and allowed to run for one hour at ambient temperature [-2.5 C]. After which the amount of chloroform
in the bottom of the vessel was measured and found to be 5.0 ml. Normally 0.85 g CHCl3 is soluble in 100 ml water corresponding to 2.2 g [~1.5 ml]
however solubility decreases with temp and I would guess there is only 1.1 ml or so left in solution.
37 g Ca(OCl)2 was added to the solution along with 10 drops commercial I2 solution for cuts composed of potassium iodide, free iodide and ethanol.
The mixture was shaken and took on a white color. Five ml HCl was added which was accompanied by significant evolution of Cl2, the mixture was
immediately capped and shaken and the stopper was very difficult to remove due to the solvation of the Cl2 thus liberated and the vacuum produced.
This procedure was repeated until 50 ml 28% HCl solution was added. The mixture ended up as a cream color which maintained a slight coloring of Cl2
gas above the solution. The mixture was allowed to react for one hour (in the sun) throughout which time the mixture bubbled.
Now, while I wait for it to complete, my methodology here is that Chlorine + Iodine even in water produces ICl which reacts with CHCl3 to produce HCl
and I2 and CCl4. So, iodine was added as a catalyst to the solution left over from chloroform production with the chloroform at the bottom. And
calcium hypochlorite was added to produce the Cl2 insitu. The reaction should progressively get more acidic to as the actual reaction produces HCl.
So HCl was added to make the solution definitely acidic and the reaction allowed to progress. The boiling point will be the main test, but also due
to the decreased solubility of CCl4 and increased weight there should be a noticeably larger amount, e.g., if I had 4.5 ml CHCl3 @ 25C in this
mixture, I should end up with 7.45 ml CCl4 at the end, so today that will be my indication that this reaction is running well. If my final yield of
non-aqueous liquid is over 7 ml.
I just went out to check on it, it's been 20 minutes. The solution was almost pink and clear. A layer of precipitate mixed with organics had
settled to the bottom. So I shook it thinking that magnetic stirring would have helped about now. This caused massive gas evolution and blew the top
off almost causing me to loose the contents. Note that when I shook it last it created a vacuum inside the container and no more Cl2 was generated,
this time the gas was most definitely Cl2 again. So I would say the reaction is definitely progressing.
As of an hour and a half into the reaction thick oily yellow/green drops have taken to collecting on the surface and suddenly dropping to the bottom.
I am left wondering how much of my product may have left the reaction vessel when the top popped awhile ago. The sedimentation is now distinctly
floating on top of the organic layer at the bottom. The reaction continues to progress with the evolution of gas.
An Update to come upon completion.
I found a reference the other day for yet another method to make CCl4, passing COCl2 over heated activated carbon produces a mixture of CO2 and CCl4.
[Edited on 3/13/2005 by BromicAcid]
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chloric1
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Hmmm!
So, you didn't even separate the CHCl3 before catalytic chlorination? Interesting to see what this deveolpes into. MAybe the greenish droplets
would be white on with a sodium thiosulfate solution washing. Got pictures? I bet it looks really cool
Fellow molecular manipulator
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BromicAcid
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It's been 3 hours and it's still reacting and making gas and chlorine on shaking. If I leave it the evolution of gasses slacks off
significantly and it separates with a layer of precipiate and under that green organic liquid drops. If I shake it the drops cling to the bubbles at
the surface and drip back down (see attachement). I'm going to let it go a little while longer, filter it and check yield. I did this all in
'one pot' because carbon tet is less soluble then chloroform by a margin and I was hoping to squeeze a little more yield out of this.
Update: Decided that it had gone on long enough so used a pipette to pull up the liquid at the bottom and filter though glass wool. But the liquid
was too hydrophobic. It would not go though the glass wool even if I tried to press it through with a stopper. So, I took the 500 ml flask and
cleaned it out and added 200 ml water and dumped the glass wool and liquid on the glass wool into the flask and shook it up. The green liquid became
clear and started to sink to the bottom again. Still, I didn't run any tests, just finished up for the day. No clue if it worked or not.
Slow addition of HCl through a sepretory funnel while the contents of the container were under magnetic stirring would have helped immensly.
[Edited on 3/13/2005 by BromicAcid]
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chloric1
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Well, that organic layer is definately denser than aqueous solutions. At least that is promising. Buy the way CCl4 has an order quite distinctive
from chloroform. This maybe one test. Also, CCl4 freezes at -23C. Unfortunately, chloroform was added to carbon tet to lower the freezing point for
fire extinguishers. So there may be enough CHCl3 to keep it from freezing at -23C. I will try to think of another test, but right now I am drawing
blanks.
Fellow molecular manipulator
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Hermes_Trismegistus
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Refractive index?
I am rather puzzled by the prior methodology, it seems that evolution of chlorine gas and synthesis of water would be all that would be produced by
the addition of HCl to a solution of CaOCl.
The problem with getting that last proton off the CHCl3 is the electronegativity of the other three Cl's repulsing (strongly the further addition
of another Cl.
But the CHCl3 does want to give away it's proton pretty bad, if you bubbled hot chorine through the chloroform and condensed the
resulting liquid....
You do have a bubbler, 24/40 and condensor set right?
Maybe use that CaOCl and HCl to produce the chlorine, and run it through a length of copper pipe with a bunsen burner under it and bubble that into
your chloroform using a thermometer inlet as your gasket?
Know what I mean....... jelly-bean?
Arguing on the internet is like running in the special olympics; even if you win: you\'re still retarded.
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BromicAcid
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Well, what I was going for was the insitu production of ICl from the chlorine being produced and the iodine present. ICl reacting readily with CHCl3
to produce carbon tet and the iodine being recycled. Just hoping to do it in a one-pot synthesis and recover some of the solvated CHCl3 while I was
at it.
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Magpie
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I have read this thread and it seems that whether or not CCl4 can be made from CHCl3 via free radical addition of chlorine is, so far, inconclusive.
I want to try it with my freshly made CHCl3. I'm planning to bubble chlorine into CHCl3 at about 50C while it is being irradiated with UV light from
a halogen bulb (probably about 11,000 candlepower). So, what is the opinion of the forum members. Is this going to work or not, i.e., give me at
least a 50% yield? I realize I will likely have to separate the CCl4 from unreacted CHCl3 and byproduct CCl3-CCl3.
The single most important condition for a successful synthesis is good mixing - Nicodem
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garage chemist
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I am quite sure that it will work. I thought of giving this reaction a try myself, but then I got some CCl4 from somewhere else.
I think the best approach would be to bubble chlorine into refluxing chloroform with irradiation by strong light (UV or halogen floodlight).
For determining the endpoint of the reaction, it would be very convenient to install a thermometer into the flask.
The reaction mix is kept boiling constantly by heating from below while bubbling in the chlorine.
As the CHCl3 reacts and CCl4 accumulates in the mix, the boiling point of the mix will rise, and when the thermometer indicates that the boiling
point of the mix is the one of CCl4 the reaction is done. The same is done with benzyl chloride synthese from toluene, I used this method and it
worked beautifully!
Fractionation of the product will still need to be done, because of the C2Cl6 (although the amount of this will be very small).
You should wash your chloroform with conc. H2SO4 before the reaction (several times, until the H2SO4 stays clear), to remove acetone residues from its
preparation.
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S.C. Wack
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It is listed as the original (1840) preparation and was recommended by Schorlemmer in 1873 as the preferred method, so it has that going for it.
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Magpie
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Thanks garage chemist and S.C. Wack for your helpful input. I will give this a try once I accumulate a little more chloroform and buy a gas
dispersion tube with the fritted glass end.
Using reflux sounds better than 50C. Using temperature to monitor the reaction and tell the endpoint is quite clever. 
The single most important condition for a successful synthesis is good mixing - Nicodem
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The_Davster
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I was thinking a while back, and actually posted it as an edit in the nitromethane thread, with no response, but would chloroacetone undergo the
haloform rxn to give carbon tetrachloride? Or would you get chloroform and sodium chloroacetate? Or even just simple chloroform and sodium acetate?
I can try it of course as I have a few g of chloroacetone, but I don't really like working with it...And it would be difficult to determine between
chloroform and carbon tetrachloride on small scale.
I also came across an old ~25 year old bottle of 'dry cleaner' with no brand name, and not much info beyond 'contains chlorinated solvent' and it
smells like chloroform, but a richer, deeper and less sweet smell. Could this be carbon tetrachloride? Carbon tet was the origional drycleaning
solvent.... Oh and the bottle is 110 ml with about 15-30 mL left in it.
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Magpie
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I don't know why chloroacetone wouldn't go right to chloroform if treated with Ca(OCl)2 under haloform conditions. But this is just a guess.
I suspect what you have is indeed carbon tet for the reason you have stated. I have a funny (to me) story related to that. I recently called a dry
cleaning place to see if they had a pint (250mL) of carbon tetrachloride they could sell me. She said "Oh, we don't use any wild chemicals here we
use Perc." Isn't Perc = perchloroethylene?  I don't think she had ever heard
of carbon tet as it's use was likely before her time. I asked if she would sell me a pint of Perc. She said "No, we are not allowed to sell that to
individuals." Same old crap. 
The single most important condition for a successful synthesis is good mixing - Nicodem
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Esplosivo
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Chloroacetone, following a haloform, would probably give the chloroacetic acid salt and chloroform. Infact I have a plan to synthesize chloroacetic
acid using this method. The chloroform produce will also be a great byproduct and easy to separate from the ionic products.
I can buy perchloroethylene as a solvents here (they call it Perchloric ethylene (Solvent 509:900)), although I have little interest in it, since I
mostly use DCM and chloroform as solvents.
Theory guides, experiment decides.
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kclo4
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well i dont know if this would work... but I think it would
if you took a small amount of NCl3 and added it to a chlorine/chloroform solution, the chloroform might react with it like this:
CHCl3 + NCl3 = CCl4 + NH3
but of course there is chlorine disolved in it, so it would just be turned back into NCl3
would NH4Cl added to a chlorine solution work to make NCl3?
if so it might be added to chlorine/chloroform solution and work just fine
sorry i dont know, if what i am saying is just tottal crap but i am in a hurry ttyl
(if i can i will edit it later but i really got to go right now)
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neutrino
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The first problem here is safety. NCl<sub>3</sub> is a notoriously dangerous substance ready to detonate at the slightest contact with
organic material. It can be handled in chlorinated solvents (this is how early research on this compound was conducted), but I'm not sure if
chloroform will work. In any case, one speck of dust in the NCl<sub>3</sub> and BANG. It may be safer under more dilution, I don't know.
I'm not saying the chemistry will or will not work, I'm just saying that this would have serious safety concerns.
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