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Author: Subject: toluene --> benzaldehyde
ketel-one
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[*] posted on 15-9-2009 at 22:48


Right, here's the patent referred to http://www.freepatentsonline.com/1280612.pdf I don't know if you say it's not good then perhaps it isn't, one step reaction it does seem too good to be true.
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ketel-one
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[*] posted on 19-9-2009 at 01:25


Doesn't styrene undergo alkene addition to form benzyl chloride? It would be awsome if styrene can be made from styrofoam.

Edit: Oh right Markovnikov's rule... the HCl would add the wrong way.

[Edited on 19-9-2009 by ketel-one]
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[*] posted on 24-9-2009 at 22:28


Quote: Originally posted by ketel-one  
Doesn't styrene undergo alkene addition to form benzyl chloride? It would be awsome if styrene can be made from styrofoam.

Edit: Oh right Markovnikov's rule... the HCl would add the wrong way.

[Edited on 19-9-2009 by ketel-one]


Styrene has an extra carbon anyway. :p




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[*] posted on 25-9-2009 at 11:07


Benzaldahyde can be made thru the the ozoneolysis of styrene followed by either H2O2 or better still Dimethylsulfide or PPh3. To attempt to create benzyl chloride from it is just unreasonable.





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[*] posted on 7-10-2009 at 07:10


Sedit: H2O2 gives an oxidative workup yielding the carboxylic acid. Stick to Me2S or Ph3P. Not a particularly fantastic route though, as ozonolysis equipment is needed, dimethyl sulfide is volatile and smelly, and triphenylphospine is pretty expensive... although the polystyrene precursor is cheap and easy to thermolyse to styrene.
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[*] posted on 7-1-2010 at 04:34


I wonder, has anyone tried toluene oxidation through the etard process?
It was mentioned somewhere is this thread.
According to one of my old chemistry books toluene can be oxidised with chromyl chloride (CrO2Cl2)

As far as I understand the reaction that it undergoes is that: 2 chromyl chloride molecules bind with the methyl group of the toluene which then is hydrolyses by H2O to benzaldehyde.

The book states that the oxidation does stop with benzaldehyde and doesn't "over" oxidises to benzoic acid or friends.
This is confirmed by wikipedia, what ever that says :P

I have no references for this method except for the brief description of the method.
The book states no experimental procedures.

I know chromylchloride is a very nasty chemical.
Still it could be produced with acceptable safety and would not be ridiculously expensive.

Anyone?
PS dont kill me , my organics arn't what they should be.

*edit*
Fuck sorry it was mentioned on page 3 with a more detailed description.
Sorry for not properly using the fucking search engine.
Also it sucks big time.
Somehow it even seems to miss perfect matching search tags.



[Edited on 7-1-2010 by User]




What a fine day for chemistry this is.
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S.C. Wack
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[*] posted on 7-1-2010 at 14:23


After all those huge pictures were posted, one can hardly be blamed for skipping through. The experiment that I mentioned before, Perkin and Law [JCS 91, 258 (1907)] with chromyl chloride in chloroform (among other methods), on toluene (among other things):

http://books.google.com/books?id=Vuc4AAAAMAAJ&pg=PA258

[Edited on 7-1-2010 by S.C. Wack]




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[*] posted on 8-1-2010 at 05:30


The link isnt working, at least for me.
Could you please give another url or upload.
Ive done some searching but cant find alternative.




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[*] posted on 24-4-2010 at 00:01


For your pleasure-


Attachment: Prep of Chromyl chloride, Perkin & Law, JCS,1907, 91, p191.pdf (156kB)
This file has been downloaded 1377 times

Attachment: Oxidation of toluene etc., Perkin & Law, JCS,1907, 91, p258.pdf (391kB)
This file has been downloaded 1625 times

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[*] posted on 13-6-2010 at 23:54


this is a little more comprehensive
and covers both the prep of chromyl chloride
and its use on various substrates.

-----edit----------
its called 'the chemistry of chromyl compounds'
but i cant get it under 2 mb.....

but its uploaded here:

http://www.scribd.com/doc/33005325

or here

http://www.scribd.com/doc/33005325/The-Chemistry-of-Chromyl-...


[Edited on 14-6-2010 by cyclohexane]

Attachment: etard_and_solvents.pdf (160kB)
This file has been downloaded 914 times

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[*] posted on 14-6-2010 at 08:38


In this thread by Hinsky
http://www.sciencemadness.org/talk/viewthread.php?tid=6882&a...

He talks about Mn(IV) for the use in the electrochemical cell but never gave definitive yeilds. I experienced the same process a number of times looking exactly as his pictures but noticed VERY low yeilds not worth the bother till sometime after messing around with it I noticed a quote in his patent that explains why. The oxidiser is added dropwise into the toluene as its heated and stirred. I don't think anyone is going to get good results mixing the two and stirring away but has anyone tryed that method with drop wise addition into the toluene? Iv considered another run at it just never got around to it and since this thread has come to life again thought I would ask.





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[*] posted on 14-6-2010 at 15:28


IMO the etard uses cheaper reagents and has almost always 100% conversion if done properly. the final yeild should be 2 moles Benzaldhyde for every 3 moles put in as etard always follows a 2:1 ratio.

that .pdf is in the reference request section at ...dreams.ws -i tried to view it to check the link,looked like it worked,but then ffox crashed....

almost always the side-product is useful as well....say one gets 2 moles cumenealdehyde, and 1 mole acetophenone for every 3 moles in.....of the substrate. the .pdf includes a variety of preperation options including the pro's and cons, as well as a horde of substrates and solvents.

if cyclo's sources are right ( and journals seem to support it) then DCM would be a suitable replacement for carbon tet. etard seemed to like tet and carbon sulfide, but back in his day tet was acceptable to use as a fire extingisher.

of course i guess the consequences of breaking a flask here are much worse......

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[*] posted on 14-6-2010 at 15:38


Cheeper then the Mn(IV) route? I find that hard to believe. Once made all reagents other then nothing but toluene are cheeply and easily regenerate. I can't see the etard comming close to this as far as cheepness is concern as long as the dropwise addition of the Mn(IV) lives up to claims.

The Etard reaction also generates dangerous toxins that I would avoid at all cost to be honst. No need to work with danger if there is another means to an end.

Just my take on it.





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cyclohexane
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[*] posted on 14-6-2010 at 21:37




actually i was wrong, the yields are 90%.
the 2:1 rule dosent apply because different starting substrate.

3. Synthesis of aromatic aldehydes and ketones
(a) From toluene: The chief product is benzaldehyde (90 per cent); small
amounts of benzoic acid, benzyl chloride, and benzylidene chloride are formed.
CHEMISTRY OF CHROMYL COMPOUNDS 35
This is the prototype reaction first investigated by Etard (56). The general
procedure used has been described, and the yields indicated above are obtained
thereby. Reaction I is probably the only one occurring to any measurable extent.
If the addition compound is heated at 240-250°C., half of the chlorine is
driven off as hydrogen chloride (reaction 111), leaving a residue having a composition
corresponding to the formula CBH&H(Cr02C1)2. This product also can
be decomposed by water or alcohol to form benzaldehyde (reaction IV).


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[*] posted on 16-6-2010 at 02:44
Electric Benzaldehyde


Hey, I'm also interested in making benzaldehyde by oxidising toluene according to patent 808,095, however, I'll be doing it on a 1/50 basis.
I have just one question, can I reuse the oxidising mixture over and over again, assuming that I am unable to get all of the toluene and benzaldehye out of the mixture?
Because I'm hoping this procedure is a simple "plug in" and "reuse" method.

thanks
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[*] posted on 16-6-2010 at 02:49


This is a forum for amateur science, not a place for people interested in scheduled substances to get spoonfed and asking for "plug and play"-syntheses.

If you had bothered to search you would see that this patent you are referring to has been discussed earlier in this thread.
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[*] posted on 17-6-2010 at 06:16


both the Etard process and benzaldehyde are are useful for things other then whats implied. if people choose to misuse information then
its up to them to deal with the possible consequences of there action.

if everything that could be misused was not spoken of then many important things would not be learned.
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[*] posted on 8-8-2010 at 12:24


Benzaldehyde can be made pretty easily by mixing styrene, acetone, and a small amount of water (like 5% of the quantity of acetone) then running ozone into the mixture, which should ideally be kept as cold as possible to prevent the evaporation of acetone. This method of ozonolysis seems to only produce good yields with terminal alkenes such as styrene though.
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[*] posted on 19-8-2010 at 16:24


Hello there...
Once I had a paper wich mentioned the oxidation of toluenes with ammonium persulfate and Ag2SO4. But I can't find it again, even when I UTFSE. Does someone know this paper or where to download?

[Edited on 20-8-2010 by Methansaeuretier]
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[*] posted on 1-9-2010 at 11:59


So to make formaldehyde with this cell I assume you just substitute methanol for toluene? Any other parts to this that I am missing?
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[*] posted on 18-9-2010 at 10:28


Quote: Originally posted by sabbath06  
So to make formaldehyde with this cell I assume you just substitute methanol for toluene? Any other parts to this that I am missing?


It is written in the patent US 808095 that methanole will be oxidized to formaldehyde or formic acid. Using an excess of methanole will convert the formaldehyde to methylal (formaldehyde dimethyl acetal).
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[*] posted on 18-10-2010 at 11:33


Quote: Originally posted by behemoth  
Quote: Originally posted by sabbath06  
So to make formaldehyde with this cell I assume you just substitute methanol for toluene? Any other parts to this that I am missing?


It is written in the patent US 808095 that methanole will be oxidized to formaldehyde or formic acid. Using an excess of methanole will convert the formaldehyde to methylal (formaldehyde dimethyl acetal).


That patent says nothing about MAA being used as the oxidizer... I have been trying to find a post by cycloknight in which he states that methanol can be oxidezed by MAA into formaldahyde. If anyone else is interested in this feel free to correct me if I'm wrong...

Keep in mind that formaldahyde boils at -21C when pure and not caught in an Azeotrope with water. If the MAA was mixed with methanol and then heated to 50C to start the oxidation formaldehyde should boil out of solution as long as the solution is dry. Just catch the formaldehyde in DH2O and boomshockalocka 37% formaldahyde solution.

Another "easy" path to formaldehyde was found at "http://www.ucc.ie/academic/chem/dolchem/html/comp/methanol.html"

Dehydrogenation of Methanol
Methanol can also be oxidised to formaldehyde by passing its vapour over copper heated to 300 degC. Two atoms of hydrogen are eliminated from each molecule to form hydrogen gas and hence this process is termed dehydrogenation

They have have a page for acetaldehyde that says it can be made exactly the same way as above except the methanol is substituted for ethyl alcohol... This makes me wonder if benzaldehyde can be made by using toluene instead of methanol. Doubt it..
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[*] posted on 18-10-2010 at 11:33


Quote: Originally posted by behemoth  
Quote: Originally posted by sabbath06  
So to make formaldehyde with this cell I assume you just substitute methanol for toluene? Any other parts to this that I am missing?


It is written in the patent US 808095 that methanole will be oxidized to formaldehyde or formic acid. Using an excess of methanole will convert the formaldehyde to methylal (formaldehyde dimethyl acetal).


That patent says nothing about MAA being used as the oxidizer... I have been trying to find a post by cycloknight in which he states that methanol can be oxidezed by MAA into formaldahyde. If anyone else is interested in this feel free to correct me if I'm wrong...

Keep in mind that formaldahyde boils at -21C when pure and not caught in an Azeotrope with water. If the MAA was mixed with methanol and then heated to 50C to start the oxidation formaldehyde should boil out of solution as long as the solution is dry. Just catch the formaldehyde in DH2O and boomshockalocka 37% formaldahyde solution.

Another "easy" path to formaldehyde was found at "http://www.ucc.ie/academic/chem/dolchem/html/comp/methanol.html"

Dehydrogenation of Methanol
Methanol can also be oxidised to formaldehyde by passing its vapour over copper heated to 300 degC. Two atoms of hydrogen are eliminated from each molecule to form hydrogen gas and hence this process is termed dehydrogenation

They have have a page for acetaldehyde that says it can be made exactly the same way as above except the methanol is substituted for ethyl alcohol... This makes me wonder if benzaldehyde can be made by using toluene instead of methanol. Doubt it..
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[*] posted on 18-10-2010 at 12:18


Quote:
Quote: Originally posted by aax  
That patent says nothing about MAA being used as the oxidizer...


Well, it does. Read the lines 63 to 71.
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[*] posted on 23-12-2010 at 17:25


I am constructing an oxidation cell ala Cycloknight/US 808095. I have a four liter solution of 12.5 M (66.5%) H2SO4 in which I have dissolved four moles of (NH4)2SO4. This dissolved completely; upon addition of the MnSO4 I was expecting a shift in color to the yellow as seen in the photos. It appears as though my MnSO4 is not dissolving, but rather being whipped up into suspension, with a “snow drift” on one side of the beaker.

The observed color is the dirty transparent yellow of the sulfuric acid solution obscured with suspended MnSO4.

The MnSO4 I added was the monohydrate. I have applied brief heat with no effect. The MnSO4 that has settled on the bottom still has its pink hue.

I have only added two moles of the MnSO4 and I am afraid to add anymore.

Should the MnSO4 have dissolved right away? It has been stirring for about two hours.

Should I have added (NH4)2SO4 until there was some that would not go into solution (it was really close)?


UPDATE (Next Morning):

Just to be methodical I added a few grams of MnSO4 to some 35% (battery) H2SO4, swirled and observed negligible dissolution.

I also added approximately the same amount to dH2O and again observed negligible dissolution.

This morning (~12 hours later) the MnSO4 has almost totally dissolve in each.

My liquid volume is approximately 100ml, though I added much less than 40g of MnSO4.

I am building a smaller cell, on the two liter scale, so that even if there is considerable undissolved particles my magnetic stirring will be able to function.

There is still considerable, undissolved MnSO4 in the initial four liter cell.

[Edited on 24-12-2010 by 6.022x10^23]
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