| Pages:
1
2 |
woelen
Super Administrator
Posts: 8027
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
What to do with diphenyl carbonate?
I could pick up 1 kilo!!  of Acros reagent grade diphenyl carbonate in a still
sealed bottle for just EUR 4, and I could not let this go past me for this mad price 
This compound has formula (C6H5)2CO3, structure is:
(C6H5O)2C=O, in fact it is the carbonate "ester" of phenol and carbonic acid.
Now, I'm wondering, are there any interesting things I can do with this? For this small amount of money I took the risk of buying an uninteresting
chemical, but I expect that some of you will be able to point me in the direction of some fun/interesting experiments with this compound. Any ideas?
[Edited on 19-8-06 by woelen]
|
|
|
hinz
Hazard to Others
Posts: 200
Registered: 29-10-2004
Member Is Offline
Mood: No Mood
|
|
I think it's useful for "phenylations" like dimethyl carbonate is useful for methylations. Geneally it shold behave like organic sulfates and other
alkylation or phenylation agents.
Here is a good article for dimethylcarbonate:
http://www.iupac.org/publications/pac/2001/pdf/7307x1117.pdf...
Diphenylcarbonate should behave similar. An interesting experiment could be to phenylate toluene to triphenyl methane CH(C6H5)3, which is a strong
acid (due conjugation with phenyl group) The diphenyl carbonate doesn't phenylate it to tetraphenyl methane due steristic reasons, the forth phenyl
group would use to much space. More about that you could find in Peter Sykes "Mechanism in Organic Chemistry" ( My favorite Organic Chemistry
lecture)
The reaction should proceed like that:
2C6H5-CH3+2(C6H5O)2C=O ==> 2C6H5-CH2-C6H5+C6H5OH+CO2
2C6H5-CH2-C6H5+2(C6H5O)2C=O ==>2C6H5-CH-(C6H5)2+C6H5OH+CO2
I only hope toluene is acidic enough to get phenylated completly.
BTW: Would it possible to get also some of that nice stuff, are you able to ship it around europe. 4Euro for one kilo of it a too good price.
Edit: With water it should give phenol and benzene, also quite useful, what would happen if I would add HCl without a lewis acid, theoretically it
could give phenol and chlorobenzene, both quite useful.
[Edited on 19-8-2006 by hinz]
|
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
I remeber Bromic was doing some experiments trying to make organic carbonates, he should know about these. I remember that their toxicity is absurdly
low, which seems contradictory now that hinz mentioned that they can be methylating agents. I have never heard good things about methylating agents.
With reaction with hydrohalic acids you could get whatever halobenzene you want!
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by hinz
I think it's useful for "phenylations" like dimethyl carbonate is useful for methylations. Geneally it shold behave like organic sulfates and other
alkylation or phenylation agents.
[...]
Diphenylcarbonate should behave similar.
[...]
I only hope toluene is acidic enough to get phenylated completly.
[...]
Edit: With water it should give phenol and benzene, also quite useful, what would happen if I would add HCl without a lewis acid, theoretically it
could give phenol and chlorobenzene, both quite useful.
|
In no way can diphenyl carbonate behave as a 'phenylating agent'. Even phenyl tryflate can only be used as an electrophile in quite extreme conditions
so you can forget about the carbonate ester. Aryl groups are very different from alkyl groups in their chemical behavior and you can’t
generalize like this.
Toluene itself is not acidic enough for reaction with any known alkylating reagent.
Hydrolysis of diphenyl carbonate gives phenol only, which is probably the most useful product you can get from it, especially since there is quite
some discussion on phenol production on this forum.
…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!
|
|
|
woelen
Super Administrator
Posts: 8027
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
I tried to make phenol from the diphenylcarbonate, but it simply does not work. The best I obtain is a faint phenolic odor, but no detectable
quantities otherwise (e.g. the test with iron(III) did not show any phenol).
I added diphenylcarbonate to a strongly alkaline aqueous solution, hoping that it would hydrolyse to phenol and sodium carbonate. I boiled for a
while. The only thing I get is that the diphenylcarbonate melts. It does not dissolve in water. The hot liquid has a faint phenolic odour, that's all
 .
Is there any way, in which I could make phenol from this compound? I have 1000 grams of it, unlocking the phenol from it would be a very good use for
it, otherwise I just have a fairly dull chemical, which does not dissolve, nor react.
[Edited on 28-10-06 by woelen]
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
you could send some to me and I can try to make this Ellusive Phenyl Oxalate ester I`ve been trying to synth for over a month now 
Just a thought 
\"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)
|
|
|
chromium
Hazard to Others
Posts: 284
Registered: 27-6-2005
Member Is Offline
Mood: reactive
|
|
| Quote: | Originally posted by woelen
I tried to make phenol from the diphenylcarbonate, but it simply does not work. The best I obtain is a faint phenolic odor, but no detectable
quantities otherwise (e.g. the test with iron(III) did not show any phenol).
I added diphenylcarbonate to a strongly alkaline aqueous solution, hoping that it would hydrolyse to phenol and sodium carbonate. I boiled for a
while. The only thing I get is that the diphenylcarbonate melts. It does not dissolve in water. The hot liquid has a faint phenolic odour, that's all
.
Is there any way, in which I could make phenol from this compound? I have 1000 grams of it, unlocking the phenol from it would be a very good use for
it, otherwise I just have a fairly dull chemical, which does not dissolve, nor react.
[Edited on 28-10-06 by woelen] |
Try to boil it in fairly concentrated solution of NaOH or if this does not work, use NaOH dissolved in ethylene glycol.
When all think alike, then no one is thinking. - Walter Lippmann
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by woelen
I added diphenylcarbonate to a strongly alkaline aqueous solution, hoping that it would hydrolyse to phenol and sodium carbonate. I boiled for a
while. |
This is not a ionic reaction. It takes time and efficient stirring, especially if biphasic. You should let it reflux for at least several hours in
20-30% NaOH. Perhaps it would be best to let it reflux in 20% HCl so that you would avoid the neutralization step (the hydrolysis is over when no more
CO2 evolves). Mind that phenol does not crystallize unless dry, so don't forget to dry the extract with Na2SO4 or MgSO4. You will also have to
recrystallize it in order to remove impurities.
…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!
|
|
|
hinz
Hazard to Others
Posts: 200
Registered: 29-10-2004
Member Is Offline
Mood: No Mood
|
|
With HCl half of the product will be phenyl chloride by the SNi mechanism, (like the chlorination with thionyl chloride) so I you have to boil the
product afterwards with hydroxide to get it hydrolysed. At least it will be a mixture of phenyl chloride and phenol, maybe there are few OH- that
attack it also. I would rather take dil. H2SO4 like in the acid catalysed ester hydrolysis, since it isn't a nucleophile
[Edited on 28-10-2006 by hinz]
|
|
|
Rosco Bodine
Banned
Posts: 6370
Registered: 29-9-2004
Member Is Offline
Mood: analytical
|
|
Wonder if melting it with sulfur would lead to an interesting fuel component , which could be mixed with an oxidizer like potassium chlorate or
perchlorate ?
Sulfonating and then nitrating it could be interesting also ,
probably giving picric acid .
[Edited on 29-10-2006 by Rosco Bodine]
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Woelen, the attached paper "Hydrolysis of Simple Aromatic Esters and Carbonates" (JOC, 27, 3717-3720) will give you an idea whether the hydrolysis is
faster with bases or acids. I don't have the time to read it so I can't say. Of course, they used a cosolvent since they had to have a monophasic
system (due to kinetic studies) but the hydrolysis will proceed without a cosolvent as well, it will just take more time. In any case it seems you
will have to let it reflux at least 8h to be sure.
| Quote: | Originally posted by hinz
With HCl half of the product will be phenyl chloride by the SNi mechanism, (like the chlorination with thionyl chloride) so I you have to boil the
product afterwards with hydroxide to get it hydrolysed. |
No, I'm sorry to say but your hydrolysis pathway makes no sense. In no way can chlorobenzene form. Diphenyl carbonate is phenol ester and not
some ordinary alcohol ester, so nucleophilic substitution of the –OH group is absolutely and categorically out of play (unless we would be dealing
with extremely electron poor phenols like picric acid, etc. – but even then HCl would not be enough).
Besides the impossibility of the last stage, your proposed mechanism fails already at every stage since it assumes the non existence of the solvent
(this is something that must never be neglected, especially when the solvent is H2O).
| Quote: | Originally posted by Rosco Bodine
Sulfonating and then nitrating it could be interesting also, probably giving picric acid. |
Diphenyl carbonate is less nucleophilic, meaning that it is less activated for nitration. You would need slightly harsher conditions for a
trinitration to occur (in other words: you would not have to worry of creating only tar, as with plain phenol). More interestingly, the lower
activation means you can selectively mononitrate it and hydrolyse in one pot (for example: like in US4788346).
Attachment: Hydrolysis of Simple Aromatic Esters and Carbonates.pdf (398kB)
This file has been downloaded 738 times
…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!
|
|
|
vulture
Forum Gatekeeper
Posts: 3330
Registered: 25-5-2002
Location: France
Member Is Offline
Mood: No Mood
|
|
It can be used to detect radical species in a reaction. IIRC it turns blue upon addition to an organic solvent which is dry and contains some
sodium/potassium. Any trace of water or any other radical quenching agent and it won't do that.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
this may be of use, I`m trying it now as I type, should take about a week to get a reasonable result with a 40 hour half-life.
2.2.3
Stability in Water
Diphenyl carbonate hydrolyses in the presence of water forming phenol and carbon dioxide. In a
preliminary study on the abiotic degradation of diphenyl carbonate in water the test substance had a
half-life (t1/2) of 73.5 h at 23 °C (Bayer AG, 2000c).
Due to the above mentioned result a study on the abiotic degradation of diphenyl carbonate
according to the Directive 92/69/EEC, C.7, was performed. It was concluded that at pH 7 a half-life
(t1/2) of 39.9 hours at 25 °C was expected (Bayer AG, 2001).
I did the NaOH thing, there`s nothing appreciable happening there either.
I fear to do this Properly, it`s simply a Patience game.
\"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)
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
update, a few days, and there is definately Gas bubbles being liberated inside the flask, I have an airlock on the flask (water based) but as yet I
can`t smell any Phenol odour?
the temp is kept at average 30c.
a further thought occurred to me, if I raise the PH a little this May help the reaction along, But I don`t want to force compounds, I figured Calcium
hydroxide may be an ideal, it`s unlikely to react with the Phenol directly and ruin it, but it will shift the PH and become reasonable inert calcium
Carbonate that I can filter out later with ease to leave my dissolved Phenol.
does this sound Viable?
\"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)
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
What exactly are you doing or trying to achieve? I have a very hard time following what you are up to.
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
quite simply DPC in water, to hydrolize to Phenol and CO2.
it has a half life of ~40 hours in water at STP, with excess water the Phenol is soluble also, the air lock is there to allow the CO2 out but not the
phenol or water.
\"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)
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
I still don't get it. What is wrong with the normal methods?
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
again, quite simple, I don`t have a large amount of this material to risk low yields and/or losses (7.5g to be exact).
and so, the most Simple procedure is preferable here, also I lack certain apparatus required for more complex methods, as you can see, my hand is
Forced somewhat towards more Mundane means of obtaining this result.
\"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)
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
a Month+ later I just looked at my Long-Term experiments shelf and I have Phenol growing up the insides of the test tube!
I made a 50/50 mix of DPC and NaOH (by volume) and 10x that amount of water, it was then heated until all dissolved and melted, then allowed to cool
and dust covered and put away for storage, all the water has evaporated leaving phenol crystals all up the inside of the test tube.
now I just need to think of a way to isolate the phenol from the Sodium salt, Water`s out of the question, perhaps 100% EtOH?
I think next time I`ll powder these crystals rather than use them as the flake form.
\"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)
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
You can not have phenol there after you used excess NaOH for the hydrolysis. Utmost you have a mixture of moist NaOH, Na2CO3 and sodium phenolate. You
need to acidify, extract the phenol, wash the extract, dry over Na2SO4 or MgSO4 and remove the solvent. Beware that phenol is hygroscopic so you can
not just acidify with HCl and filter the precipitate.
…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!
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
I`m inclined to agree, although the Smell is Very phenolic, I`ve just covered it in pure EtOH and little to non dissolved, when I just read your post
I added a few drops of 30% HCl and there was Plenty of fizzing (I assume it`s CO2).
the excess NaOH is probably all Carbonate now as the crystals up the inside of the tube were all bone dry.
I`m hoping as the Phenol from the Phenolate gets trapped quite nicely in the EtOH now leaving NaCl crystals at the bottom.
it may also be worth noting that my attempt at just the Water and DPC left with an airlock on the radiator for a month did very little beyond a trace
smell of Phenol, so this "40 hour half life" doesn`t seem to work all that well in practice, I wouldn`t reccomend it to anyone.
\"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)
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Chemical degradation half lives are values true only for monophasic systems. If you have a mixture of diphenyl carbonate and water, the half life
value will only be true for the diphenyl carbonate that is dissolved in water. Hence you can not generalize the half life of 40h to cases like yours.
I don't even understand why you bothered when the kinetics of diphenyl carbonate hydrolysis are measured and described in the paper I posted earlier
up the tread.
Sodium phenolate should smell like phenol since it partially decomposes to phenol due to the absorption of CO2 and H2O from air.
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
well it`s Thanks to that paper you posted, that I`ve gotten results that far outstripped the plain water method I worked on, I got 2.5g
dissolved/reacted in less than 48 hours, compared to the Miligrams over a Month+
at the moment I`ve just letting all the water evaporate off to leave my Sodium Phenolate (and excess NaOH).
then I`ll add HCl dropwise until the PH is below 7 and evap again, leaving phenol and NaCl, I`ll then dissolve all the phenol in EtOH and filter off
the NaCl, and evap the EtOH.
Thanks for your help and Corrections, your method is Indeed Very Viable/workable and I Will at last get some Phenol
\"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)
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
You better stick to the workup that I suggested earlier. The one that you suggested will not give you a pure enough product and you will have a hard
time crystallizing it. You should know that wet (and impure) phenol simply does not dry on air (if it crystallizes at all!).
Edit: Sticking to conventional methods is better simply because there is generally a good reason for why they are conventional.
[Edited on by Nicodem]
…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!
|
|
|
JohnWW
International Hazard
Posts: 2849
Registered: 27-7-2004
Location: New Zealand
Member Is Offline
Mood: No Mood
|
|
Thanks, nicodem, for the info. However, several browsers and download clients cannot handle https sites.
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
