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YT2095
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well I`m Still experimenting with DPC, and have made some simple Reflux apparatus to this with.
the NaOH soln and DPC works quite well, and after about 7 hours of reflux a clear brown liquid is seen and there`s no molten DPC floating, here:
I`ve tried using CaOH as the base, hoping that it will lock up the CO2 and so simple filtering is all that will be needed to leave Phenol water, oddly
rather than the Brown color seen in the above pic, this is a salmon Pink?
here:
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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garage chemist
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I dont think calcium hydroxide is a strong enough base for the hydrolysis, also some calcium phenolate would be in solution.
NaOH is really your best bet, just acidify the reaction mix and extract phenol with ether, DCM or CHCl3, dry the organic phase (MgSO4, Na2SO4) and
distill off the ether to leave phenol.
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YT2095
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the only problem is that they are both water based, I thought I`de try the Ca(OH)2 as when I add the sulphuric acid, the PPT will just stay in the
filter paper leaving a phenol water mix (and maybe a trace of Sulphuric acid).
the idea was to boil off most of the water at this point since phenols BP is higher.
and then extract with a solvent.
the strange thing is that when the cold condenser pipe drips back into the hot mix, the drips are a clear brown color.
I`m thinking perhaps I should just distill the whole lot after acidifying, that way no Sulphuric or Sulphate salts are going to come over, and neither
will the DPC as that`s all been converted.
phenolic water maybe a nice place to start from, I can alway put this in a bottle and forget it until I get more time.
my plans of making Diphenyl Oxalate are not possible anyway, I realise this.
I have to learn more about transesterification before I try making it, so that`s yet another Adventure for me 
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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unionised
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I think phenol will steam distill over with the water.
I also don't see what's wrong with
1 boil it with NaOH (which is cheap, water soluble and a very strong base)
2 Acidify with HCl/H2SO4/ whatever's cheap and easy.
3 Extract with ether or DCM (pet ether won't work in case you wondered)
4 Dry and
5 Distill off the solvent.
(6, if you are feeling brave distill the phenol)
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YT2095
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I have Di-ethyl ether (aka Engine Start), but isn`t that water soluble?
how would I do step 3?
also it`s worth noting that, the Ca(OH)2 does work rather well, but it does need more hours under reflux, it still stays salmon pink, but gets deeper
pink, and ppt in there is no longer pure white as it when 1`st added, that is actually Flesh tone, I could sell the crap to the Avon Lady
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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garage chemist
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You can't boil off water from phenol water, the phenol will boil off first! Its a classic example of steam distillation.
Diethyl ether is only slightly water soluble, its used as an extraction solvent in the organic laboratory very often. The only important thing is to
dry the ether extract, since diethyl ether dissolves quite a bit of water.
Alternatively, you could steam distill the phenol after acidifying with H2SO4. That way you get pure phenol water as the distillate, which will give
colorless phenol upon extraction with ether.
The brown color is due to autooxidation and metal complexes of the phenol, phenol is very prone to discoloration.
You dont even have to lead in steam to do the steam distillation, you can just distill off most of the water from the acidified solution. You will
likely see two phases in the receiver at the beginning, one of them is ca. 90% phenol with some water dissolved, the other is water with some phenol
dissolved.
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YT2095
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ok, I`ll do that, and stop when I notice the second phase, I think 90% is a great place to start from.
edited to add:
I just acidified the mixture here, I used 5ml of 98% H2SO4 (seemed silly adding More Water by using diluted acid), it got quite hot even though it was
added dropwise, and stunk of Phenol, quite a remarkable Color change though! Here:
as you can see the ppt is Pure white now and the liquid is a light yellow/orange.
now it`s Filtered, Here:
[Edited on 23-9-2007 by YT2095]
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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Nerro
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Am I really missing something or is hydrolysis using aqeous HCl also an option? The carbonate should be converted into CO<sub>2</sub> and
two equivalents of phenol. I noticed the mechanism by Hinz but frankly it makes no sense at all. The predominant nucleophile would be water which
means that there would be carbonic acid and phenol formed. Also it makes no sense at all to let the nucleophile (Cl<sup>-</sup> in his
case...) attack the C on the phenylring rather than the "carbonyl-C" of the carbonate. Even in the case that a stray chloride ion would act as the
nucleophile the product would almost instantaneoulsy be hydrolysed by all the water. Sulphuric acid would do the job equally well and even make the
work-up easier as all you need is CaCO<sub>3</sub> or Ca(OH)<sub>2</sub> to get rid of the sulphate.
Why do you guys prefer to use a base?
#261501 +(11351)- [X]
the \"bishop\" came to our church today
he was a fucken impostor
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courtesy of bash
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The_Davster
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I have observed diphenyl carbonate decompose to phenol before, during heating at over 100C for 24h in methane sulfonic acid. After 24h the condenser
above the hot solution/melt was absolutly full of long phenol crystals.
The methanesulfonic acid could perhaps be replaced with conc. H2SO4 and heated with diphenylcarbonate for a day with a condenser or coldfinger above
it to collect the phenol. Nice thing is the anhydrous conditions allow the pretty phenol crystals to form.
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YT2095
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I`v had the DPC crystalise into needles when I`v had to turn off the heat (I can`t be in here all the time during reflux), and they look really nice,
but are Very delicate too.
well I`v started distilling the phenol soln as shown in my last post here:
ignore the stacked tin cans, I don`t have a propper jack yet.
and this is the distilate, you`ll note it`s quite clear and not at all yellowish, and it Reeks of Phenol! here:
there doesn`t seem to the 2 phases though? as the distilation is nearly complete now.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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YT2095
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just an interesting factoid I never knew until just and thought I`d share it here (the more advanced chemists can ignore this).
I stopped the process at the phenolic water stage and bottled it, I tested the PH with universal indicator paper (ph1-11 range) and it`s not at all as
acidic as I thought it would be, the paper color hardly changed at all from Neutral!
I added a few drops in to a testube that contained equal amounts of 50% H2SO4 and 40% HNO3, after a few seconds the liquid went bright red and clear,
there were also some yellow flakes form (very tiny and floating).
so it shows that there is Definitely good phenol in there as it made Mono and maybe even a little bit of Di nitrophenol.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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