Organikum
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Call for discussion of several methods of producing pyruvic acid by dry distillation
I present here several methods of thermal dehydration followed by decarboxylation of tartaric acid and would like to discuss their
feasibility
First method, from Vogels 3rd:
]
=============================================
Second method from OrgSyn:
| Quote: |
Organic Syntheses, Coll. Vol. 1, p.475 (1941); Vol. 4, p.63 (1925).
PYRUVIC ACID
Submitted by J. W. Howard and W. A. Fraser. Checked by C. S. Marvel and R. L. Shriner.
1. Procedure An intimate mixture of 600 g. (4.4 moles) of finely powdered, freshly fused potassium acid sulfate and 400 g. (2.7 moles) of powdered
tartaric acid, prepared by grinding them together in a mortar, is placed in a 3-l. round-bottomed Pyrex flask connected with a condenser which is
filled with water but does not have any water flowing through it. The mixture is heated by means of an oil bath maintained at a temperature between
210 and 220° until liquid no longer distils over. Some foaming takes place (Note 1), but, if fused potassium acid sulfate is used and the temperature
of the bath does not rise above 220°, it is not difficult to control. The distillate is then fractionated under reduced pressure. Pyruvic acid passes
over at 75–80°/25 mm. and the yield is 117–128 g. (50–55 per cent of the theoretical amount) (Note 2).
2. Notes
1. If the mixture foams badly, it may be kept from frothing over by heating the upper part of the flask with a free flame.
2. The cake left in the reaction flask may be removed readily by inverting over a steam jet. |
=============================================
Third method after patent US4136111:
=============================================
Fourth method after patent DE281902:
A short translation to the german patent which I found in the Ullmanns but there they told that ethylene glycol can be used for the dehydration,
something what made me wonder but optimistic. But it came out otherwise....
The patent starts with explaining the prior art of dehydration of substrates containing hydroxyls and the compounds used - potassium bisulfate and
pyrosulfate, zincchloride, but states that the compounds are to strong and lead to various sidereactions and a "smearing" of the reaction mass.
They found out that it can also be done by using glycolic acid or glycolide (what is, if I am not mistaken, dehydrated glycolic
acid). Glycolic acid and glycolide work also as solvent/thinner and the obnoxious foaming is avoided. The reaction can be done under STP as under
reduced pressure.
Now to the relevant example 3:
Equal parts of tartaric acid and glycolic acid are mixed and fractionally distilled. First almost pure water distills over. At 140°C the receiving
flask is changed and up to 160°C highly concentratedpyruvic acid distills over which is pure enough for many uses withoutn the need for further
purification. Also the water which came first contains large amounts of pyruvic acid which can be recovered by distillation under vacuum. The residue
in the reaction flask is reconstituted to glycolic acid by the addition of water.
============================================
Discussion
The Vogels and OrgSyn are basically identical, they differ slightly in yields. The use of a mixture of potassium bisulfate and pyrosulphate (fused)
prevents excessive frothing but is bad for the yields.
But it for absolutely sure will work as described!
The US patent controls foaming mechanically and claims higher yields this way, the approach sounds logical but technically not trivial. Advantages
besides yields are: No need to fuse the bisulfate and to grind it with the tartaric, the addition of sulfuric acid to the potassium bitartrate should
provide a good mixing and at least for me potassium bitartrate is about 30% cheaper then tartaric acid (counted on the acid) as is H2SO4 cheaper then
KHSO4.
Are there other ways to prevent foaming, would heating the flasks top suffice, would SS-wool pretreated with H3PO4 be resistant against the acids
involved (in special not react with the substrate and product?
Would it be feasible to prepare the mixture with bitartrate/H2SO4 and to add a certain amount of STRONGLY fused bisulfate or bought pyrosulfate?
The german patent is nice - if it works. In the olde times they often left something out and thats my fear here too.
Their claim that the pyruvic acid comes over up to 160°C tells us that they must have applied some vacuum - not so much, but some. Pyruvic acid boils
at 165°C. On the other hand they say that a lot of pyruvic acid comes over with the water at the beginning. Wouldnt this say that adding more water
when the temperature rises to high will make a simple steamdistillation out of this? I suspect that temperature has to be limited for not to turn the
glycolide formed from the dehydration of the glycolic acid into polyglycolides which I doubt can be regenerated to the acid by simple addition of
water. Thats more some plastic then.
I also found this schematic on the net:
It was also a description of prior art, but what puzzles me is that in the decarboxylation step they name Me+ aka metal ions as promotors of the same.
In the german patent there are no metal ions, are they just unnecessary or is this what the guys forgot to tell.
Wouldnt the german method so it works not call for a permanent process, say to refill tartaric acid from time to time as it is used up?
And last not least: Why does the MERCK say that glycolic acid is always used when one wants a very cheap acid of this kind, why then does my chem
supplier want 15€ (USD 20)for a meager 100 gram - industrial quality.
Further (practical) methods, suggestions, simple foam-control devices, other usable mild dehydration agents...
Everything welcome
regards
/ORG 
[Edited on 15-5-2007 by Organikum]
<sub>(Edit by Nicodem: Added a page break at the last picture to correct the frameset of the thread.)</sub>
[Edited on 1/3/2008 by Nicodem]
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Sauron
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It's repetitious to include the Vogel procedure which he simply downsized a little from the Org.Syn. prep. The latter is more detailed anyway. Sure,
the Org.Syn. procedure is itself largely based on earlier publications but at least those were referenced and acknowledged; usually, modified and
improved and appended.
Vogel cadged a lot of that, removed the underpinnings and the references, abbreviated and condensed the procedures to the point of (occasional)
unclarity. Don't get me wrong; Vogel's is a useful work. But 90% or more of the procedures are cribbed and from a single source, without attribution.
It borders on plagiarism.
Here's the complete Org.Syn. article with footnotes and references.
Noteworthy that the "Dobner" reference from Ann. in 1887, which solo and I spent time searching for for Organikum, was sitting in reference 5 of this
article all along. <sigh>
All of the references in Ber. through 1901 are availoable for free at the gallica site. The Ann. der Chemie and post 1901 Berichte references can be
found on Wiley and requested at References. The Annalen der Physik reference, is available free from a British site (see References for details).
With patents one is always on shaky ground until you do your own confirming experiments.
[Edited on 16-5-2007 by Sauron]
Attachment: CV1P0475.pdf (133kB)
This file has been downloaded 924 times
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roamingnome
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im still betting on commerically availble calcium pyruvate which has two pyruvates for more pyruvating action.
but then i already see a gack war starting when things catch up.
thereby makng pyruvic acid distillation necessary in the end.
i like drafting, so blaze on you founders you....
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Organikum
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Has anybody something to contribute except wiseassing?
I really thought I compiled an exemplary post with some questions added.
What I get is dumbass comments.
Why?
/ORG
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roamingnome
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logicly speaking ole chap, it is becuase you dont like us
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Sauron
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Often with a foaming problem like this you can handle it by switching from the 3L flask specified to a 5 L flask instead. The extra volume does the
trick.
The text does say that foaming will not be unmanageable unless you fail to regulate the oil bath temperature as described.
I do agree that heating the upper half of the flask with a free flame is not my idea of a good technique in an organic lab.
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vulture
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| Quote: |
I do agree that heating the upper half of the flask with a free flame is not my idea of a good technique in an organic lab. |
Possibly. But it sure works for killing foam creeping up. Contact should ofcourse be in the range of seconds.
(vacuum) Distillation with foamy stuff is best managed with a bunsen burner because you can remove the heat source at any time. Good luck trying to do
that with an oil bath.
[Edited on 15-5-2007 by vulture]
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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leu
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| Quote: | | Good luck trying to do that with an oil bath. |
Using a lab jack to support the oil bath simplifies lowering it quickly  Using
heat guns and/or infra red lamps to heat the upper portion of the flask could possibly work better 
Chemistry is our Covalent Bond
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Matchheads
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I loved it , (your post Organikum) even before you complained that ppl were adding comments which were not helpful. I don't think that's true. I
think they were reading it as a critic, as a skeptic.
I do like free flames in the lab. That's what's acceptable. The existence of the Bunsen burner tells us that.
a) One old book (I forget the name) was by a guy who liked to say he had tried things as recommended and had come up with his own way. One was to
leave a glass tip hanging down with a charred cork on it which was at the receiving end of a condensor. If you firmly twist a receiver onto a cork
you have flamed it will stick there, even after it fills up. This is counterintuitive. Try it.
b) I don't like heating bath oil, I only like silicone oil. It is $75 a gallon, but you can heat it way up and it won't smoke. Cooking oil really
smokes, especially right up where you have to leave it. This pyruvic acid thing is high-heat.
c) The idea that an "organic lab" must be full of flammable solvents should be re-examined. If you focus on changing that, you can do it. Yes, I
have to buy a gallon of acetone to get a price break. However, acetone is just a wash solvent. The gallon sits outside. My wash bottle is red. The
tip it comes with produces too generous of a stream. Therefore, I hold the tip in my free flame and grab it with some needle-nose pliers and pull the
soft plastic out. I snip that off at about 1.5 mm diameter. When I store the wash bottle, I remove the siphon downtube, or the bottle will empty out
when I'm not around due to the high vp of acetone. I keep new paint cans around to stick things like this in, or I just stick it in the refirgerator,
but then I don't have a bowl of tuna fish in there, too.
d) In Journal of Forensic Sciences, 1983, Dr. Frank, head of the DEA chem lab, says that a new method of producing methamphetamine has appeared
using hydriodic acid, red phosphorous, ephedrine, and carbon disulfide. It was like if I asked you what has four wheels and flies and has cement in
it, I just put the cement in to make it hard, and it's a garbage truck. Dr. Frank knows CS2 is the most flammable common solvent. He just sticks it
in there. The rxn doesn't need it. The article's called, "The Clandestine Laboratory Situation in the United States".
Silicone is a foam breaker, but we are famous for not putting extra things in. Heat's okay. Organikum, the word you wanted for a rxn that keeps on
going is "continuous", not "permanent".
Yeah, you're good. You can scan things in and all that. I don't want to get out of this window, I am not comfortable that my reply will not be lost,
but, Organikum, I predated your post with the word, "pyruvate" in another thread. My subject was the Rohm and Haas patent for ephedrine. You have
not stated why you want pyruvic acid, but if its in this vein I can't blame you. It would be instructive to post the entire synthesis for ephedrine,
but, it takes methylamine. I am predicting that for raw meth, D-
phenylalanine by-product of aspartame is going to become the path of least resistance.
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Sauron
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@matchheads:
Right. Free flames in the lab. I guess you don't work much with ether, CS2, THF, methyl formate, acetals, vinyl acetate or other extremely volatile,
low-flash point solvents and reagents, huh?
Common in an ORGANIC lab. Why did you put quotation marks around "organic"?
@leu
Good advice on both counts. A heat gun (not a fucking hair dryer, but a real lab heat gun) would be a proper way to do that.
And a lab jack is almost a necessity in a setup with a water bath, oil bath, fusible-metal bath, or sand bath. Even for mantle support they are a
great convenience. I have three old Cenco ones I bought for a song on LabX. They turn up there and on eBay often.
[Edited on 16-5-2007 by Sauron]
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Organikum
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I came up with the following ideas:
For the bitatartrate/H2SO4 method: Using an improvised hot-air bath which keeps the temperature of the whole flask + head at about the same, possibly
adding a certain amount of fused KHSO4. A heatgun will be by hand.
Otherwise or additionally some SS-wool passivated with H3PO4 will be put in the flask, hopefully the parts protruding over the surface are hot enough
to destroy the foam.
For the glycolic acid method: Well I will just have to give it a try I guess, a continous process seems possible, my only question remaining is if
there shouldnt be some catalytic amount of metal added to aid dcarboxylation, and if which metal in which form.
Any suggestions?
regards
/ORG
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Sauron
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An airbath like the Kugelrohr oven for the old 4 liter model that is no longer made would be good. not too tricky to improvise and rig for thermostat
control.
Let us know if the patents get you anywhere beyong 50-60%, I'm sure that would be of general interest. I don't have a crying need for pyruvic acid,
but then, I don't have one for citrazinic acid and look at all the time and effort I put into that prep.
Hey @matchheads, your ref to the former DEA lab chief's advice about putting the CS2 in the lab fridge before using open flame in the lab was not
entirely unreasonable, but, but, but. First but: it does not account for fumes that tend to accumulate near the floor (like ether) and that form
explosive FAMs. But, Dr Franck is referring to a LAB refrigerator, almost certainly an explosion proof model, and how many of us have one of those
handy? I have a very well equipped lab and I don't have a laboratory refrigerator. They are costly new, and buying a used one in USA (wrong voltahe)
and shipping it to Thailand makes little economic sense. The freight would be god-awful. In summary, Bunsen burners etc have their place mostly in an
analytical lab for ashing in Pt crucibles, that sort of thing. But we are talking about an organic lab, and I seriously doubt that we are going to
turn our science on its head just to only use non-flammable solvents. That is ass-backwards.
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vulture
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| Quote: |
Using a lab jack to support the oil bath simplifies lowering it quickly Using
heat guns and/or infra red lamps to heat the upper portion of the flask could possibly work better |
And how is a heatgun safer than a bunsenburner? The exhaust of a bunsen burner is water and carbon dioxide, with a heat gun your blowing hot air,
which contains oxygen (duh!), with a temperature well above the flashpoint of what you're distilling.
Pull away the bunsen and the heat is gone. Period. If the setup explodes it's because you didn't check the glass, not because you're heating with a
bunsen. Bunsen or not you'd be fucked anyway. Good glass will take some pretty heavy abuse from a orange flame.
[Edited on 16-5-2007 by vulture]
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Sauron
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Fine. You use a free flame in the lab. Go right ahead. Be my guest. Meanwhile I'll buy some marshmellows and look for some long sticks. Haven't
toasted any marshmellows for a longish time. This should be an excellent opportunity.
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vulture
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| Quote: | | Fine. You use a free flame in the lab. Go right ahead. Be my guest. |
I always use(d) a bunsen burner for vacuum distilling my products at the uni, along with many of my colleagues. It's safe if you take the necessary
precautions. I also know labs where they are ridiculously paranoid about this stuff and guess what. They don't get any work done because they're too
busy buying and installing fancy equipment. They also have alot more accidents because they're not used to think anymore with all those machines doing
the work for them.
And if you think distilling oxidizing liquids in an oil bath is safe, well...
[Edited on 17-5-2007 by vulture]
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Sauron
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I doubt I'd use peanut oil if distilling oxidizing liquids. Silicone oil, on the other hand, is pretty damned inert.
I doubt I'd distill nitric acid from sulfuric acid in a glycerol bath. An extreme example.
I am not married to an oil bath. I mostly use mantles. Sometimes air baths, water baths. Occasionally sand baths, or liquid-metal baths.
But not a free flame.
Fuel-air mixtures will ignite regardless of the paranoia level of the chemist or lack thereof.
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vulture
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| Quote: |
Fuel-air mixtures will ignite regardless of the paranoia level of the chemist or lack thereof. |
Guess what. You don't necessarily need an ignition source to get an explosion if your setup undergoes catastrophic failure. When you're going from
saturated with distillate vapor to air, you're usually passing through the explosion limits of organic liquids. A hot piece of glass or your bath will
suffice to ignite that mixture.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Sauron
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Oh true enough. Still, you would idly light your Zippo (now a fashionable antique cigarette lighter...) while filling your gasoline (petrol) tank
would you?
Anyway we have wasted enough of Polverone's electrons on this. I doubt either of us has swayed the other. Go in peace and try not to look like Richard
Pryor.
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Organikum
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This board is not anymore what it was a short time ago.
A pity.
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roamingnome
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after reading the patent more fully its seems this is just a stairt foward procedure
since cream of tarter is a waste product of the "never going away" wine industry pyruvic acid supply should be available.
Simethicone, is an oral anti-foaming agent used to reduce bloating, discomfort and pain caused by excess gas in the stomach or intestinal tract. It is
a mixture of polydimethylsiloxane and silica gel.
if silica gel does not effect the reaction it might produce a better heat transfer and even help foaming
shoot, do I even need to say microwave!
its a pity your to dam judgmental these days ORG
if i still recall its the world wide web, not let me remenis about the good times.com
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Organikum
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| Quote: | Originally posted by roamingnome
im still betting on commerically availble calcium pyruvate which has two pyruvates for more pyruvating action.
but then i already see a gack war starting when things catch up.
thereby makng pyruvic acid distillation necessary in the end.
i like drafting, so blaze on you founders you.... |
Which calcium pyruvate is also a dihydrate and practically insoluble in water. Ever minded to look into a MSDS before talking out of your ass?
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roamingnome
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if we are refering to the useing of said CaPyruvate for a biphasic biotransformation
my calculations which im checking twice
indicate that 2M ethanol will be part of the water layer in addition to a lysis salt buffer probably at pH 6.8, maybye this will help my ass....
What will it disolve in? my mind is always open....
pH plays a role in solubility
another pot shot at a jovial little gnome
your going to see some cool stuff soon so keep your pants on
my real query is useing imines directly without reduction
i cant find any information on imine carbamylation.. but thats totaly off topic...
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LSD25
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Um, has anybody suggested 'Dalapon (r)': (http://www.alanwood.net/pesticides/dalapon.html), it is a halogenated propionic acid herbicide which breaks down to give predominantly pyruvic
acid apparently...
Here is a link to the first page of an article on the photolysis of the same:
http://links.jstor.org/sici?sici=0033-7587(197306)54%3A3%3C388%3APO2AIA%3E2.0.CO%3B2-Y
Here is a link to the chemical data on the product:
http://cameochemicals.noaa.gov/chemical/21722
As a herbicide, it is sold as a white powder in large bags at a fairly convenient price per kilo.
PS It is also known as 'Propon (R)'
Whhhoooppps, that sure didn't work
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Organikum
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What about an ion-exchange on the calcium pyruvate?
| Quote: | Originally posted by roamingnome
if we are refering to the useing of said CaPyruvate for a biphasic biotransformation
my calculations which im checking twice
indicate that 2M ethanol will be part of the water layer in addition to a lysis salt buffer probably at pH 6.8, maybye this will help my ass....
What will it disolve in? my mind is always open....
pH plays a role in solubility
another pot shot at a jovial little gnome
your going to see some cool stuff soon so keep your pants on
my real query is useing imines directly without reduction
i cant find any information on imine carbamylation.. but thats totaly off topic... |
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