Sciencemadness Discussion Board - Potential uses of Citric Acid

Potential uses of Citric Acid

ssdd - 25-4-2007 at 12:36

Ok so I recently got my hands onto a fair amount of citric acid. After searching around I couldn't find too many uses for it. I know it can be used in the production of HMTD, but what else can it be used for?

(I have a particular interest in organic chemistry and plants if any one has anything involving those that would be great.)

Edited title to make it more descriptive. Chemoleo.

[Edited on 25-4-2007 by chemoleo]

Nicodem - 25-4-2007 at 12:49

You can make trialkyl citrates, di(m)ethyl acetone dicarboxylate, aconitic acid anhydride, citrazinic acid and its N-alkyl derivatives and so on...

12AX7 - 25-4-2007 at 13:47

(If it's a good grade!), add it to citrus foods. Lemony

Huh, it occurs to me that "trialkyl citrates" would be a structurally close inverse of triglycerides. Hmm, there are two methylene groups and an extra hydroxyl in there outside of what would be the closest inverse. *Shrug*

Tim

ssdd - 25-4-2007 at 14:03

It seems to be of a fairly high grade though I am not positive. How would one go about testing the purity of something like that?

I am searching around for some of those suggested compunds, doesn't seem to be much info out there but I'll keep looking.

chemoleo - 25-4-2007 at 15:35

You can make nicelooking citrate complexes, i.e. ammonium ferrous citrates etc.
If you look around here, there are a number of threads dealing with this.
Also, citric acid can be converted to acetone dicarboxylic acid (again, search), it has multiple uses for a variety of things, including generation of heterocyclic rings etc.

Nicodem - 25-4-2007 at 23:27

You can get the procedure for acetone dicarboxylic acid and its esters at the Org. Synth. server. Citrate esters are used in cheap perfumes and deodorants so there must be a bunch of patents describing the esterification of citric acid. Similarly you can find a bunch of patents on aconitic acid anhydride and citrazinic acid synthesis.

ssdd - 26-4-2007 at 07:51

On the MSDS sheet for citric acid it said that when mixed with a metal nitrate that the mix becomes rather unstabe and is prone to explosion.

Has anyone ever had experience with this or tried it?

I'm still looking around for the makings of diffrent citrates etc.. Ill post if I find anything good.

Nicodem - 26-4-2007 at 11:04

Using MSDS's as a source of data for chemical properties is plain stupid. These things are not even compiled by true chemists anyway. Besides many organic compounds become "rather instable" when mixed with metal nitrates. It is just a mater of definition of what "rather instable" stands for.

PS: Have you never made any mixtures of sugar and KNO3? Well, that is just about it.

Mr. Wizard - 26-4-2007 at 15:53

Quote:

Originally posted by Nicodem
Using MSDS's as a source of data for chemical properties is plain stupid. These things are not even compiled by true chemists anyway. Besides many organic compounds become "rather instable" when mixed with metal nitrates. It is just a mater of definition of what "rather instable" stands for.

PS: Have you never made any mixtures of sugar and KNO3? Well, that is just about it.

I think chemists and engineers have input into the compilation of data on the MSDS. It's made to be a rough reference for worst case scenarios when tanker loads or truck loads of material are involved.

Your example of sugar and KNO3 is a good one.

This kind of 'common knowledge' among chemists is not readily apparent to firefighting and emergency response crews who would be using the MSDS information. They are usually not well informed about this type of thing. Before you dismiss the MSDS sheets, remember that many of the references are gleaned from hard learned experience and real world experience at high cost.

It is made to be an interface between the technically knowledgeable and the people who actually have to deal with the accidents in the real world. I would be willing to bet you would be very glad to look at one before you approached a railroad tank car pile-up, with a variety of unfamiliar chemicals.

Just because you aren't a chemist doesn't make you stupid.

Nicodem - 26-4-2007 at 22:10

I agree about the use of MSDS info in safety and emergency cases, but not when it comes to chemical properties. Like you said: "It's made to be a rough reference for worst case scenarios when tanker loads or truck loads of material are involved."
As such it can only be a source of disinformation to the chemists. Chemical properties are not worst case scenarios, but everyday scenarios. This however does not mean that MSDS are an extremely important source of information for the non-chemists who mainly deal with non everyday scenarios. But obviously many members here still don't know the difference as I often see this idea of using MSDS instead laboratory handbooks as a source of info about chemical properties.

Sauron - 26-4-2007 at 22:52

Citric acid to acetonedicarboxylic acid and its esters is done with fuming sulfuric acid (oleum). The original publication by Pechmann in Ber. (1884) employs concentrated sulfuric acid, but it was the same author who introduced the use of oleum somewhat later. I am getting the original paper translated so we can see how yields compare. Obviously conc H2SO4 would be much more convenient for just about any of us. Fuming sulfuric is bloody expensive.

The free acid is unstable.

The esters are stable is carefully washed free of sulfuric acid traces.

Acetonedicarboxylic anhydride is also stable, and a rather interesting compound.

The most famous uses of these compounds is in Robinson type Mannich condensations to construct the tropinone bicyclic system.

[

[Edited on 27-4-2007 by Sauron]

bketoglutaricanhydride.jpg - 2kB

Axt - 27-4-2007 at 01:25

Quote:

Originally posted by Sauron
Citric acid to acetonedicarboxylic acid and its esters is done with fuming sulfuric acid (oleum). The original publication by Pechmann in Ber. (1884) employs concentrated sulfuric acid, but it was the same author who introduced the use of oleum somewhat later. I am getting the original paper translated so we can see how yields compare. Obviously conc H2SO4 would be much more convenient for just about any of us. Fuming sulfuric is bloody expensive.

I've uploaded the original paper here http://www.sciencemadness.org/talk/viewthread.php?tid=2969 though sadly yields were not stated, nor was the synthesis detailed. I tried it once with concentrated H2SO4 though yields on this attempt were poor.

woelen - 27-4-2007 at 02:04

Citric acid can also be used in Bhelousov-Zabotinsky type of oscillating reactions. Usually these are carried out with malonic acid (which is hard to obtain), but citric acid can also be used instead. The only drawback of using citric acid is that the solution becomes turbid with this and some oily compound is formed, while with malonic acid, the solutions remains clear. Hence, with malonic acid, the result is more visually pleasing.

Sauron - 27-4-2007 at 03:33

@Axt,

Thanks for the input. Yes I know yields with oleum are very good (90+%) while those with conc H2SO4 are not so good. However, oleum costs me a lot of money (65% fuming sulfuric from Merck, about $900/L, admittedly 2 Kg but even so.)

I have two liters of the 65% Merck product but I'd rather keep it for a more significant project.

How bad are the yields? Even if only 20-30% I'd still rather squander (cheap) citric acid and (cheap) conc sulfuric. The conversion to the ester is also very lossy. I forget how the conversion to the anhydride goes - maybe better maybe not.

I know the citric acid needs to be dried. I have a drying oven, etc. so this is not an issue.

Axt - 27-4-2007 at 04:31

Quote:

Originally posted by Sauron
How bad are the yields?

The first post in that thread shows what I done, thus from 50g citric acid (presumably monohydrate, bought from grocery store) yielded 12g ADCA though this was only press dried as I had no reason to free it from the H2SO4, so a good portion of that was the residual acid. It was a one off attempt following no published procedure so it could well be improved upon.

Gee thats expensive for oleum though, 'bout 3.5x more then it is here (Australia) for the same Merk 65% fumin' H2SO4. Though even $260ish per litre seems way too much.

Sauron - 27-4-2007 at 04:46

It was 65,000 Thai baht for 2 liters of the 65% product.

Now I figure the dealer clipped me for a good 100% markup, as I discovered on another purchase later. So perhaps if I bought it today from a different reseller who only clips me for 50% or so you could knock 25% off those numbers.

And 1 liter of 65% can be dilted with conc H2SO4 to more than 2 L of 30% or 3 L of 20% oleum. That starts to be a bit less insane although the dilution process is not for the faint of heart, a lot of heat is evolved. So it must be done slowly w/stirring.'

Anyway let's see, you started with 50 g citric which you did not dry and you got a crude yield of 12 g ADA which is properly isolated might have been 9 g really.

That's not really bad. The Org Syn process starts w/700g dried citric acid and gives about 500 g of the purified ADA. But that's with oleum and yours is with acid so cheap it may as well be free.

Thanks, that's very useful.

ssdd - 27-4-2007 at 14:00

Ok so I was bored today in my chem class and had some time. So not really having much in mind I tried the Citric Acid/Nitrate mix.
I knew going into it as was warned it wouldn't be anything to fancy.

The first one I ran was Citric Acid and Cadmium Nitrate - Cd(NO3)2
I tried a match lighting which gave nothing, and then a Mg strip with no results. As a last resort I put the burner directly on it. It gave off a yellow red smoke (this was done in a fume hood) and stained the ceramic dish green. I couldnt get it to self sustain due to the fact that it was hydrated Cadmium Nitrate (I missed that part on the bottle.)

I ran a second experiment using Potassium Nitrate. This one worked out much better, but still needed the burner to light it. Once light it self sustained and bubbled, blowing off alot of black smoke. It burnt with a red flame with small amounts of purple (potassium I guess) in it. There was a fair amount of black residue left behind.

I know not to many are interested with this, but if anyone has the equation for whats going on that would be great...

DeAdFX - 27-4-2007 at 17:41

What were your weight ratios for Citric acid and KNO3? Prehaps it might burn with less residue if your change the ratio a bit?

Nicodem - 27-4-2007 at 23:46

Quote:

Originally posted by ssdd
The first one I ran was Citric Acid and Cadmium Nitrate - Cd(NO3)2

Cadmium nitrate! My god! Think of the nature. Ecology and all! I don't mind if you ruin your health, but think green.

Sauron - 28-4-2007 at 00:24

The conversion of acetonedicarboxylic acid to its cyclic anhydride (sketched above) is by treatment with acetic anhydride. I suspect that phthaloyl chloride will do the same. Oxalyl chloride too. However, those are by analogy whereas the Ac2O method is a lit. procedure and goes in 84% yield.

The anhydride is then used to prepare the monomethyl ester which is preferred in the classical Mannich condensation to various naturally occuring tropinone systems.

That mono-esterification is a quantitative yield according to the lit.

Seems to me that the acid could be monoesterified directly by modifying the Org.Syn. prep of the di-ester.

Or, rhw di-ester could be half-saponified to the mono ester.

But maybe those procedures would give mixtures not easily seperated and yields might suffer. In any case there would be little advantage in terms of time and labor.

For about 30 years I have been reading about this stuff in connection with synthesis of 2-CMT and thus the ecgonines and a passel of diastereomeric cocaines. This subject was well covered on Rhodium, q.v. if interested but in no wise can this compete with the economics of the natural product so it is quite academic and the stereochemistry is pretty daunting. The resolution requires the unnatural isomer of tartaric acid, which is bloody expensive last time I looked. So, while a very pretty synthesis, I'd advise anyone interested to hone their skills on pseudopelletierine which will be frustrating enough but won't get you tossed in jail. Not an easy prep.

ssdd - 28-4-2007 at 04:09

Quote:

What were your weight ratios for Citric acid and KNO3? Prehaps it might burn with less residue if your change the ratio a bit?

I ran it at a 50/50 ratio yesterday just for the sake of saving some time. But after running it in a equation solver I see that I should run it at KNO3 - 606g Citric - 384g or about 2/1.5.

Nicodem - 28-4-2007 at 07:19

Citric acid monohydrate is not appropriate as combustion fuel for such mixes. Actually it is one of the worst choices. Being a monohydrate the evaporating water takes a lot of enthalpy while 3 out of its 6 carbons are already nearly fully oxidized (the COOH groups) so they are nothing but dead weight inhibiting the propagation of the combustion. You should try with charcoal. That works better and if you add a tiny bit of sulfur as well you have the good old gun powder.

ssdd - 28-4-2007 at 08:00

Ok that makes the slowness of reaction rate make more sense.

I have done alot of work with charcoal and metal based powders, I just thought this this would be something a little diffrent.

The acetonedicarboxylic acid sounds like it could be fun to try, I may give that a run later this week.

Thanks for the info.

Nicodem - 30-4-2007 at 21:02

Quote:

Originally posted by ssdd
The acetonedicarboxylic acid sounds like it could be fun to try, I may give that a run later this week.

Beter start with something simple as citrazinic acid. If you have no experience in preparative organic chemistry, I don't think the preparation of acetonedicarboxylic acid and its esters is something to start with.

ssdd - 1-5-2007 at 07:44

Quote:

Ok, but after some searching around all over the place, I can not find a single drop of information as to how to make citrazinic acid. There seems to be nothing on orgsyn or on the forums. If anyone can give me a link to a page with info or tell me a good method it would be greatly apprechiated.

Also: What are some possible uses for this?

[Edited on 1-5-2007 by ssdd]

Nicodem - 1-5-2007 at 08:10

If you have no better means you could search the patents like I already told you. There are several very simple methods there. Else you can search the scientific literature at publisher's homepages.
Citrazinic acid is prepared by heating citric acid monohydrate with ammonia or preferably urea to 120-150°C (see the patents for details). The yield is generally moderate (~50%) but this is irrelevant given how cheap and available both starting materials and potential solvent are.
As for its use, I don't know and you never said the product has to have any special use, but preparing a 2,4,6-substituted pyridine, even if such a simple one, is a nice way to learn heterocyclic chemistry in its preparative aspects.

ssdd - 1-5-2007 at 11:49

Ok thanks, I managed to dig up some info where you said. Now I'm trying to figure out the best masses to use of each material (urea and citric acid). The equation solver came up with it being an "impossible reaction."

As to uses really anything, but I'll find something on my own to save the trouble. Thanks for being patient with me I know I can be a bit of a pain...

Sauron - 1-5-2007 at 20:23

citrazinic acid is 2,6-dihydroxyisonicotinic acid

Look at your citric acid, think about how ammonia (anibe groups) are going to add to it, and how the resulting intermediate will end up cyclized and aromatic with a N in the ring adjacent to (surrounded by) a pair of hydroxyl substituents.

It's actually quite elegant getting from boring old citric acid (but not boring to a biochemist, think Krebs cycle) to an aromatic heterocycle in one step with ammonia (urea) in a single step with just a little heat to give it a nudge.

Think amide -> keto/enol. The middle carboxylic group in citric acid is the one that ends up in the 4-position (sometimes called the gamma-position) in the pyridine ring. The hydroxyl group eliminates as H2O giving rise to a pi bond that stabilizes the two enols. Ta-da! Let me know if you still can't see it in your head and I will draw you a picture.

The overall reaction consumes one mol ammonia per mol citric acid and releases three mols water as steam.

So much for stoichiometry, I'd use urea. If you use ammonia you'll spend a lot of time eliminating the excess water. Dry distillation of the two solids (citric and urea finely ground and intimately mixed) will work. I have used this for preps of succinimide and phthalimide from the dicarboxylic acids. An alternative to urea is ammonium carbonate. Use whichever one is easier for you to obtain.

See the patent(s) for workup details. I have not read them. This is an easy mechanism to figure out.

Oh, since you start with citric acid monohydrate you drive off four mols water per mol citric acid.

As to use, I have found only one article in all of ACS journals dealing with its use (and none on its preparation).

Wiley and Kraus, J,Org.Chem 21, 757-758 (1956)
3-Arylidene-5-(-hydroxybenzylidene)-2,6-piperidinedione-4-carboxylic Acid -Lactones from Citrazinic Acid
I have that one if anyone wants it

An older British paper I have requested that hopefully details the preparation and workup of the acid.

LXXIII.—Studies on citrazinic acid. Part I
W. J. Sell and T. H. Easterfield, J. Chem. Soc., Trans., 1893, 63, 1035
DOI: 10.1039/CT8936301035

Here's my surmise on the mechanism. I am not suggesting that all of these intermediates are isolable, they are included for clarity. The last two are the main tautomers.

[Edited on 2-5-2007 by Sauron]

citrazinic.jpg - 15kB

Nicodem - 2-5-2007 at 02:09

An ancient RSC paper on citrazinic acid requested by Sauron in the Wanted references:
LXXIII.—Studies on citrazinic acid. Part I
W. J. Sell and T. H. Easterfield
J. Chem. Soc., Trans., 63, (1893), 1035 - 1051.

Attachment: Studies on citrazinic acid Part I.pdf (1.1MB)
This file has been downloaded 1369 times

Sauron - 2-5-2007 at 05:15

Why thanks @Nicodem, very obliging of you. I just found an even hoarier paper from Ber. pp 2681-2699 (1884) on the amides of citric acid and their use in pyridine synthesis, and spent some time pulling up 20 pages one at a time in Gallatica and assembling them into a pdf. All the gory details are there, for those who are not German-challenged. For those who are, including myself, I am sure the J.Chem.Soc. paper will be a welcome respite.

It seems the scheme I sketched above is off on stoichiometry. Three mols ammonia are required as the citric acid is converted to citramide before cyclizing. The German paper includes preparation of that triamide as well as the diamide so one could if they wish do this in two stages, isolating the citramide first.

Also turns out that the main use of citrazinic acid is as a component of Kodak's E-6 Ektachrome color process. Isn't that interesting?

Furthermore if you halogenate citrazinic acid at the 2 and 6 positions with, say, POCl3, and then reduce the resulting compound you obtain 4-picoline (4-methylpyridine.) Probably the world's costliest picoline, because the stuff is cheap and there's little real point in making it from citric acid. But it's nice to know it can be done. Most likely that reduction could be effected selectively (by judicious selection of reagent) to give isonicotinic acid, which is much more interesting. This could save me a messy oxidation with permanganate, which is what I have a couple liters of gamma-picoline sitting here for.

--------

After reading:

Damn, only 25% yield? That's rather discouraging. But apparently the ammonium hydroxide methods are even less efficient. I bet they'd go better in an autoclave.

I have citric acid and urea aplenty (hence my interest) also ammonium carbonate. Maybe I will give this a try.

[Edited on 2-5-2007 by Sauron]

Attachment: Binder1.pdf (1MB)
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Nicodem - 2-5-2007 at 08:58

The US2752354 patent claims a 50-60% yield of citrazinic acid and similar yields for citrazinamide as well. From the little that I understood a couple of Czechoslovak patents with essentially the same method also claim similar yields, so apparently it is possible to get to 50% with this procedure using ethylene glycol as solvent.
If you want to use an autoclave and do the reaction in water solution with ammonia then there is the patent US2729647.

Sauron - 2-5-2007 at 10:50

Yes I just finished reading the Pfizer patent (aq ammonia, ammonium citrate, heat and pressure) and the followon patent on purification. I have not seen the ethylene glycol solvent process yet but clearly, that bp makes all the difference.

I also found the Org Syn procedure for aconitic acid. Rather unsurprisingly from the structure it is similar to the procedure for acetonedicarboxylic acid but weaker sulfuric acid is used albeit at higher temperature. <94% you get aconitic, 94% or higher, acetonedecarboxylic.

Unfortunately there is no Org.Syn entry for citrazinic acid, oh well. I requested parts II and III of that J.Chem.Soc. series plus an earlier one by same authors. I am curious about just what acetanhydrocitric acid might be.

Nicodem - 2-5-2007 at 11:34

The other requested papers are cited bellow and attached in the Zip file:

V.—Studies on citrazinic acid. Part II
T. H. Easterfield M.A., W. J. Sell M.A., F.I.C.
J. Chem. Soc., Trans., 65 (1894) 28 – 31.

LXIV.—Studies on citrazinic acid. Part III.
W. J. Sell F.I.C., M.A. , T. H. Easterfield M.A.,Ph.D.
J. Chem. Soc., Trans., 65 (1894) 828 – 834.

LXXXIV.—Anhydro-derivatives of citric and aconitic acids.
T. H. Easterfield and W. J. Sell
J. Chem. Soc., Trans., 61 (1892) 1003-1012.

PS: Besides the aconitic acid at Org. Syth. there is also the procedure for the preparation of another simple derivative of citric acid, the itaconic acid and its anhydride which can be thermally isomerized to citraconic anhydride.

[Edited on by Nicodem]

Attachment: Some papers on citric acid derivatives.zip (1.1MB)
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UnintentionalChaos - 2-5-2007 at 15:47

I am currently following the procedure linked by nicodem 3 posts back. I am using glycerol (since they said it works) and the whole mix is being heated in a somewhat temperature unstable oil bath. Fluxuations +/- 10 degrees celcius (which is within their acceptable range). Once the mix got up to temperature, there is significant outgassing of ammonia (constant bubbling), though very little seems to be escaping the erlenmeyer. It has also become a fairly dark brown color, probably from some of the glycerol breaking down. As far as I know, all the reagents were quite pure to start with. USP glycerin, food-grade citric acid, and non-fertilizer urea that was snow white when added. I'd like to see if the glycol is a better solvent, but I'm fresh out. I'll give you an update tomorrow on yield since it runs for 4 hours, followed by the necessity of drying the product. Going to citrazinic acid from there will come later.

EDIT: The mix should really be kept at or just above 133C since that is the decomposition temperature of urea and the bubbling stops almost completely 5 degrees below that. I've tinkered with it and gotten it to stabilize at about 135C which isn't bad.

[Edited on 5-2-07 by UnintentionalChaos]

Sauron - 2-5-2007 at 17:43

Just woke up and was pleased to find a further gift from @Nicodem to start off my day. Will go unwrap the package after this post. Last thing last night read the Aries patent (which @UC is already running) and will be very interested in his results. While I just bought a nice stirred autoclave, it is not of infinite capacity. So being able to work in glass at atmospheric pressure is a good thing. I'll also like to see if the oil bath is really necessary or whether a well regulated mantle and a mechanical stirrer would serve as well.

@Nicodem, triple thanks again. I'll go unwrap it now.

Grrr. The present did not unwrap. WinZip barfed on it and so did WinRAR. Not a valid archive. @Nicodem, would you mind attaching those three files, one by one? You could do so in prior posts in this thread, if you wish, I will keep an eye out for them.

Thanks.

[Edited on 3-5-2007 by Sauron]

leu - 2-5-2007 at 19:30

There's nothing wrong with Nicodem's archive; if at first you don't succeed, try try again

Sauron - 2-5-2007 at 19:54

Already tried, tried again 5 times. With both WinZip and Win RAR no go. Tried opening, tried saving, tried right clicking and Save As.

WinZip and WinRAR are working fine with other files.

I dumped cache, rebooted router, rebooted PC, changed HDD, changed from XP Pro SP2 to SP1. No go. "Invalid or corrupted" is the diagnosis of WinZip, WinRAR and the file compression utility built into XP SP1.

As the one who requested these files, I'd rather like to get to see them. So I would appreciate it of someone would post them, one by one, in uncompressed pdf form. I am NOT having any problem with zip files in general, just this one. I am NOT having problems with pdf's.

[Edited on 3-5-2007 by Sauron]

UnintentionalChaos - 2-5-2007 at 21:19

Ugh, something wen't terribly wrong with this synthesis. I expected some degree of burnt material/sideproducts, but the final reaction mix looks just like motor oil. Upon acidification I got...nothing! I will let it sit for a while since it wouldn't be the first time something took a while to ppt for me. The only compound in the mix that should have decomposed at the temperatures involved (including the worst fluxuations) should have been urea and the chemicals I used seem to be of good quality. I will have to try this again with ethylene glycol and see If the same mess happens. Maybe someone with a more stable heating system or guaranteed clean reagents could give it a shot. The hottest it ever got was @12 degrees over their 133 standard, though I quickly dropped the temperature when this occured. This is the result of trying to do this over flame since I don't have a functioning hot plate at the minute. The oil bath was an attempt to stabilize rapid fluxuations in temperture since I was constantly raising and lowering the burner to increase/decrease the temperature and maintain it in acceptable range. I failed to find a stabilized perfect temperature during the entire 4 hours.

Nicodem - 2-5-2007 at 22:22

Quote:

Originally posted by Nicodem
V.—Studies on citrazinic acid. Part II
T. H. Easterfield M.A., W. J. Sell M.A., F.I.C.
J. Chem. Soc., Trans., 65 (1894) 28 – 31.

I don't know if it is the Zip file that is corrupted (the copy on my HD is OK) but something certainly is wrong with the attachment either at the file level or at the board level, because I'm unable to download it today while I'm able to download other attachments in the thread normally. I suspect something went wrong yesterday when I tried to edit the post and instead it disappeared into a post containing only the attachment. I rescued the text from the cache and reedited thinking the only thing damaged was the text of the reply. Maybe I hit some forum bug or whatever. Anyway, I'm reposting the papers uncompressed one by one:

Attachment: Studies on citrazinic acid Part II.pdf (227kB)
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Nicodem - 2-5-2007 at 22:24

Quote:

LXIV.—Studies on citrazinic acid. Part III.
W. J. Sell F.I.C., M.A. , T. H. Easterfield M.A.,Ph.D.
J. Chem. Soc., Trans., 65 (1894) 828 – 834.

Attachment: Studies on citrazinic acid Part III.pdf (377kB)
This file has been downloaded 880 times

Nicodem - 2-5-2007 at 22:27

Quote:

LXXXIV.—Anhydro-derivatives of citric and aconitic acids.
T. H. Easterfield and W. J. Sell
J. Chem. Soc., Trans., 61 (1892) 1003-1012.

Attachment: Anhydro-derivatives of citric and aconitic acids.pdf (584kB)
This file has been downloaded 876 times

Nicodem - 2-5-2007 at 22:41

Weird! Now I'm able to download the Zip, but it does not open as a Zip file. After inspecting the file content in notepad I noticed that it is not even defined as a Zip since it does not even start with the "PK" declaration as it should.
The moral of the story is that from now on I will avoid editing the posts containing attachments. :mad:

Sauron - 2-5-2007 at 22:57

Thanks, @Nicodem. It was making me crazy all morning.

You reckon the archive was corrupted by editing the post it was attached to? Must be part of the new improved MySQL I guess...better inform @Polverone.

Of those last three articles, so far as I can tell from a quick look the most interesting is the earliest one preceeding the three part series.

"Acetanhydrocitric acid" is obtained from citric acid and acetyl chloride. As soon as I finish studying this paper I will report.

Okay, anhydrous citric acid is treated with 4 mols acetyl chloride per mol, and warmed on steam bath for two hours under reflux. This gives a nearly quantitative yield of what Sell and Easterfield called acetanhydroacetic acid, but what I would call acetylcitric anhydride and what IUPAC names as a substituted tetrahydropyran. I base my choice of acetylcitric anhydride on the fact that Sell and Easterfield treated this substance with water and obtained acetylcitric acid.

When treated with concentrated ammonium hydroxide at 130-140 this substance gives 30-40% citrazinic acid on workup. We know from the teachings of later workers that if this reaction is run in an autoclave, thus precluding loss of ammonia, much higher yields could be expected.

As we have elucidated the facile preparation of acetyl chloride and acetic anhydride by a variety of routes (TCT, benzoyl chloride, phthaloyl chloride etc) the reagent presents no great difficulty. This may be an alternative in case the urea method as taught in the Aries patent (plyhydroxy solvents) proves difficult.

[Edited on 3-5-2007 by Sauron]

CZA.jpg - 11kB

Sauron - 3-5-2007 at 14:13

Sorry about the double post.

@UC, heads up. See following from Ullman's. This might throw some light on your problem and cast doubt over the Aries patent.

"Citric acid is easily esterified with many alcohols under the usual conditions in the presence of a catalyst, such as sulfuric acid, p-toluenesulfonic acid, or an acid ion-exchange resin; esterification with alcohols boiling above 150 °C requires no catalyst. Benzyl chloride and sodium citrate yield di- or tribenzyl esters. Trimethyl, triethyl, and tributyl citrate are used as plasticizers in food-packaging materials.
Dihydric alcohols, dihydric phenols, and polyhydric alcohols, such as mannitol, sorbitol, and glycerol, form polyesters with citric acid. In some cases the esterification reaction can be stopped before completion, leaving at least one of the carboxylic acid moieties free to form a salt; the resulting polyester may be soluble in water."

So citric acid esterifies polyhdric alcohols (that would include ethylene glycol, glycerol, and mannitol as mentioned in patent) and alcohols in general having a bp over 150 C, without catalyst. Presumably, this occurs at or above that minimum bp. You are operating close to that especially when fluctuations are taken into account.

So, did you make poly(ethylene citrate)? Wouldn't that maybe be a lot like...motor oil?

Personally I would look for a solvent that is inert, dissolves both urea and citric acid, and boils above the rxn temperature.

But polyhydroxy compounds may not be inert enough.

[Edited on 4-5-2007 by Sauron]

UnintentionalChaos - 3-5-2007 at 15:53

At least it all washed off nicely and was a small scale test. There weren't any carbon deposits, just an extremely dark brown/black mess. I suppose it was glycerol-tricitrate or something. Since each citric acid has 3 carboxyls, crosslinking is highly possible. I have some DMSO on hand, but 1: its power to dissolve everything may be an issue when seperating products 2: I've heard it tends to decarboxylate things and citric acid has everything to lose and 3: I haven't used it yet (recent acquisition) and have no idea what kind of side reactions can occur. If you think it's still plausible, I'll run the experiment, since the solvent (in both cases) is more expensive than the other reagents and none of it was particularly pricey.

Since I think the target temperature of 130-133 was to allow the decomposition of urea, but minimize esterification (if possible), the use of another solvent may make that narrow temperature gap obsolete, as long as the temperatures dont approach the decomposition point of the citric acid itself. Then again, high heat might lead to more side products, so I'll just keep it where I had it. I imagine the formation of the tri-amide is the major and unavoidable byproduct that keeps yields low.

not_important - 3-5-2007 at 18:17

If the ZIP file in question is "Some papers on citric acid derivatives.zip" I just downloaded it again and opened it without trouble, which suggests the problem isn't simple.

Regarding the citric acid - urea - polyol solvent, perhaps adding technical xylene and running at reflux would work, if there's enough xylene the temperature should stay around 140 C.

UnintentionalChaos - 3-5-2007 at 19:10

I don't think it is really a temperature issue. I am sure that it was darkening before it even got that hot. By the time it hit 130 it was starting to brown. Sauron mentioned that "esterification with alcohols boiling above 150 °C requires no catalyst," so i would assume that any decently elevated temperature will lead to rapid formation of esters. The problem in the reaction is that it is operating above the boiling point of water and therefore the formation of an ester (or the desired amide, which are both dehydration reactions) become irreversible since the water is immediately removed. I think an alternative solvent is definetly the route to go here.

chemrox - 3-5-2007 at 19:23

Quote:

The other requested papers are cited bellow and attached in the Zip file:

V.—Studies on citrazinic acid. Part II
T. H. Easterfield M.A., W. J. Sell M.A., F.I.C.
J. Chem. Soc., Trans., 65 (1894) 28 – 31.

LXIV.—Studies on citrazinic acid. Part III.
W. J. Sell F.I.C., M.A. , T. H. Easterfield M.A.,Ph.D.
J. Chem. Soc., Trans., 65 (1894) 828 – 834.

LXXXIV.—Anhydro-derivatives of citric and aconitic acids.
T. H. Easterfield and W. J. Sell
J. Chem. Soc., Trans., 61 (1892) 1003-1012.

I get an error message trying to open the zip file.

not_important - 3-5-2007 at 21:17

Ah, but

RCO2R' + R"NH2 <=> RCONHR" + R'OH

standard amide preparation, goes faster left to right and an excess of amine can drive it that way.

And I just tried the download for the 3rd time with success. What filesize are you getting?

Sauron - 3-5-2007 at 21:20

Having slept on the matter I have come to think there are two possibilities.

1. My initial reading of the Aries patent was cursory. If as I took it, the polyols are just intended to be high boiling solvents or diluents then indeed maybe they were poor choices and in that case the xylene suggestion may be an excellent one.

2. On the other hand, both the Aries patent and the Pfizer patent in discussing the background of the art, make mention of the prior art use of citrate esters rather than citric acid, in reaction with aqueous ammonia, to give citazinic acid via citrazinamide.

In light of that, a more thoughtful reading of the Aries patent might indicate that the selection of polyols like glycol and glycerol and mannitol might not be only, or even chiefly for bp but, rather, to form citrate esters in situ and react them at appropriate temp. with urea or its decomposition products, NH3 etc. Again proceeding through citrazinamide to citrazinic acid.

Maybe?

Additionally I would like to try using ammonium citrate as suggested by the Pfizer patent and ammonium carbonate as suggested by Vogel in prep of phthalimide as alternative to either urea or ammonium hydroxide. Having done phthalimide all three ways I don't see why this would not work.

Furthermore, @UC, just to get back on track why not try the dry method? Citric acid and urea. Acidify not with sulfuric but with acetic acid. Citrazinic acid does not fluoresce in water unless alkili is present. Solubility in water is very low but freely sol in base. Expect about a 25-30% yield of a yellow solid with greenish tinge.

The Aries and Pfizer patents after all are just attempts at upping the yield. (Doubling ot.)

UnintentionalChaos - 4-5-2007 at 00:20

Dry method I can do, but I am just going to sleep here (4am) and have work in a disturbingly short number of hours. I probably won't be able to give it a go until Sunday since I am swamped with work at the moment.

Concerning "2." note that the esters react with aqueous ammonia. There is water present for breaking the ester bond at which point ammonia can come in and react. I doubt the process would proceed so easily with almost no water present to enable hydrolysis. Given that the reaction temp is directly at the decomposition point of urea, I imagine that the active reactant here is the ammonia and the urea is used solely because it can generate it in situ at an elevated temperature. Fluoresce under black light I assume? Excellent "titration" there. Fortunately I have a black light somewhere.

Sauron - 4-5-2007 at 01:51

No mention made of UV. Sunlight even indirectly ought to suffice (as it does for fluorscein.)

I think I will give this (dry method first) a go myself. Have citric, have NH4OH, have urea, and ammonium carbonate, so can try all three methods before moving on to the Aries process. Can't do the autoclave method till my Parr 4521 arrives, a coupld months by slow boat after truck from Michihan to SF CA.

Meanwhile will buy some ammonium citrate tribasic. Acros has dibasic, may settle for that. Also I want to try that "acetanhydrocitric acid" method, as well. I want to start to accumulate some citrazinic acid.

For one thing, I'd like to try the conversion of it to isonicotinic acid, which is by chlorinating the two hydroxyl groups then reducing them off. The original investigators uses phosphorus chlorides, I want to try my fave alternative reagent that someone thinks I mention too much - so I won't.

^

[Edited on 4-5-2007 by Sauron]

garage chemist - 4-5-2007 at 03:11

Phenolic OH groups can be reduced to hydrogens by distillation with zinc dust. Thus, phenol gives benzene when treated that way. If citrazinic acid can be reduced by zinc would have to be tried. Maybe the isonicotinic acid decarboxylates to pyridine in the process.

Sauron - 4-5-2007 at 05:30

Don't know about the Zn dust. However the two fellows who started all this in 1884 teach that citrazinic acid, chlorinated by two mols PCl5, is then stripped of those chlorines by reduction with aq I2 to give isonicotinic acid. The three relevant pages from Ber. are attached, the entire 20 page article being a bit ponderous. I will put it up on my 4-shared.com acct and post a link here if anyone wants the entire thing. File name Binder1.pdf but feel free to rename it to something more meaningful after you download it.

http://www.4shared.com/dir/2245331/5a78115f/sharing.html

Merck cites a later article I have not been able to obtain DOI for as yet.

Wibaut, Rec. Trav. Chim. 63, 141 (1944).

Same topic, 2,6-dichloroisonicotinic acid to isonicotinic acid.

It should not be lost on anyone that this opens up an OTC route from citric acid to isonipecotic acid - piperidine-4-carboxylic acid.

[Edited on 4-5-2007 by Sauron]

Attachment: Pages from Binder1.pdf (180kB)
This file has been downloaded 890 times

smuv - 4-5-2007 at 06:04

Garage Chemist, do you have a ref. for the removal of phenolic hydroxys? I would like to read more about it.

Sauron - 4-5-2007 at 07:38

I looked over the Aries patent again. If we are to believe it, then the polyols are indeed supposed to be inert solvents. The broad temperature range of 125-140 C is given but they teach for best results 130-133 C just as @UC said.

One thing that did strike me was scale.

I can easily run 1 mol ureau and 1 mol citric acid, as a dry melt, in a 1 L flask and maybe more than that. That's 210 g citric acid monohydrate or 192 g anhydrous, and 280 g urea. The urea is added in two stages, 180 g first and 100 g two hours later.

But if I proceed per Aries, I need 900 g solvent, that's a little more than 700 ml glycerol or c.800 ml ethylene glycol. For sure I'd need to run this in a 2L flask.

Therefore for a given setup size, even if Aries process works I am going to obtain same amount of citrazinic acid, even though the yield is twice as good for the Aries process.

If I run this in my 5L flask I can get 5-7 mols in there without exceeding 50% of capacity once melted. Assuming a 25% yield, which is conservative, that's 1.25 to 1.75 mols product per batch. Roughly200-275 g citrazinic acid.

To get same amount by Aries method in same setup I'd have to do it twice.

Or go to a 12 L flask and mantle. that I don't have and would need to buy.

Given that citric acid and urea are about as inexpensive as you can get, while citrazinic acid is (per Acros) $3+/gram, the dry method looks pretty good to me. Sometimes yield doesn' tell the whole story.

Now I'm going to examine the Pfizer patent and see how much I can process per batch in my 1 L Parr autoclave. The working capacity is about 650 ml.

The Pfizer patent teached reaction of conc aq ammonia with anhydrous citric acid or preferably ammonium citrate in a pressure vessel @140 to 150 C or higher for 18-36 hours. The ammonia is employed in large excess and in concentrations from standard 28% to 53% made by adding ammonia gas to the concentrated ammonia at 0 C.

When 28% ammonia is used yields are 20-30% which is no improvement over prior art. Only by employing higher concentrations and large excess at pressure and temperature and lver a long time compared to the dry method, are the improved yields obtained, and these are somewhat less than transparent since they include about 1/3 of propduct retained in mother liquor, and recoverable by reusing said liquors. Best isolated batch tields are about 40% and that is about same as the "acetanhydrocitric acid" method described in the Sell and Easterfield series in J.Chem.Soc.

In my Parr 4521 1 liter autoclave I can at best run the Pfizer process on a half molar basis obtaining maybe 30 g product. I'd need a cylinder of NH3 and a regulator. Ouch!

In short this is not the way to go for a bench scale prep.

Both patents contain food for thought though.

[Edited on 4-5-2007 by Sauron]

turd - 4-5-2007 at 08:34

Quote:

Potential uses of Citric Acid

So far nobody mentioned the obvious: The Pechini method.

Admittedly it's neither organic nor plant chemistry.

Sauron - 4-5-2007 at 21:44

As I was saying the dry distillation (solventless melt) seems to be the most practical lab scale preparative method for making citrazinic acid. Sometimes it's not the best yield that counts, it's how much you can get out of a rxn you can run in the equipment you have!

So let's consider our options

Citric acid monohydrtate and urea

Anhydrous citric acid and urea

Ammonium citrate and urea

Citric acid monohydrate with ammonium carbonate

Citric acid, anhydrous with ammonium carbonate

Ammonium citrate with ammonium carbonate

Let's revisit Messers Sell & Easterfield.

While the Aries patent employs 55% excess ureau in their solvated scheme, Sell and Easterfield recommend 200% excess urea (540 g total) per mol citric acid. Okay, urea is cheap. Yield of citrazinamide claimed is 25%. The reaction is conducted at 155-160 C and takes about two hours, this is substantially faster than the Aries patent. A modification I would propose trying is to start the melt with half the urea and then add the other half after about 60-90 minutes, then continue heating till the mixture is semisolid.

----------------------------

The methyl and ethyl citrate esters are solids and have high boiling points. Ethyl citrate boils at 294 C for example. I found a literature procedure using dry hydrogen chloride as catalyst.

Ullmann's says ordinary acid catalysts such as sulfuric and p-toluenesulfonic acids.

[Edited on 5-5-2007 by Sauron]

Sauron - 5-5-2007 at 21:26

Apologies for double post, previous one getting cumbersome and this is a significant tangent.

Found a J.Org.Chem article concerning derivs of isonicotinic acid, in which they employed the citrazinic acid prep (from methyl citrate) then chlorinated with POCl3 (not PCl5) to obtain the 2,6-dichloroisonicotinic acid, then knocked off one Cl with hydrazine hydrate and CuSO4 and proposed to treat that with KSH to obtain the 2-thiol, in order to react with iodine to make the sulphide as an experimental tuberculostat.

The POCl3 is much more easily prepared than PCl5. It can be made from P2O5 by either treating with oxaclyl chloride, or some suggest fucing with NaCl. (The latter suggestioin was from Gattermann).

References for the chlorination and for the dechlorination are provided therein and I have requested these three articles. This will complete the citric acid to isonicotinic acid preparative route, as an alternative to the permanganate oxidation of 4-picoline, which may not be so easily obtained by some.

The JOC article is attached.

[Edited on 6-5-2007 by Sauron]

Attachment: jo01095a019[1].pdf (357kB)
This file has been downloaded 1037 times

tupence_hapeny - 20-5-2007 at 08:03

Here is an article (a fucking recent article) on the use of my very favouritest 'ghetto' style, oh so bloody OTC, reagent (shit, I am turning into Sauron) - trichloroisocyanuric acid for the esterification of carboxylic acids:

http://www.4shared.com/file/16312738/cfc4e930/Acylation_of_A...

I swear to god, I don't search for trichloroisocyanuric acid - I just seem to find the stuff whatever the fuck I search for, honest...

tup

PS For those wondering how this is on topic, at least one of Nicodem's articles refers to the reaction of ammonia with the methyl/alkyl ester of citric acid... Thus, a good way to get to that ester is provided in the article (although, whether it will work properly with a tricarboxylic monster like this is anyones guess)

Sauron - 20-5-2007 at 12:39

The rxn of ammonia with methyl or ethyl citrate to give citrazinic acid was popular in the first half of the last century but as of the mid 50s was largely supplanted by use of citric acid directly or by citric acid with urea in a polyol solvent.

So a new way to prepare citrate esters is sort of an answer to a question no one asked.

But thanks for the article. I am always interested in new things to do with TCCA and TCT.

Citric acid reactions

Random - 31-7-2010 at 14:37

I have big amount of citric acid and I want to do some experiments with it. I don't know much about organic chemistry, but I suppose that's the way of learning it. Are there some interesting experiments with it?

E-tech - 31-7-2010 at 16:37

using citric acid as a catalyst in HMTD production can be fun-
until you lose your fingers, that is.........

Random - 31-7-2010 at 23:09

Thanks for suggestion, though I am not interested in blowing my head currently

un0me2 - 5-8-2010 at 07:04

Ummm, pentachloroacetone (see attached paper) and then either the 1,1,1-trifluoro-3,3,3-trichloroacetone (from completing the chlorination to the 1,1,1,3,3,3-hexachloroacetone & then fluorinating it) or 1,1,1-trifluoroacetone by dehalogenation and then fluorination (IIRC).

Cleavage of that (or better reaction of the the ketone with amino acids to give the N-trifluoroacetate) to trifluoroacetic acid.

[Edited on 5-8-2010 by un0me2]

Attachment: Diagnosing Consecutive Reactions of Hypochlorite- pH and Oxidative Decarboxylation_Halogenation.pdf (302kB)
This file has been downloaded 837 times

Random - 21-10-2010 at 01:14

Is there something I can do in organic chemistry with citric acid? Maybe some useful product?

Nicodem - 22-10-2010 at 08:51

I don't know if your question is serious or you are just trying to entertain us, but in case you haven't realized it, this very thread is all about that topic already. So start reading it from the first post onward.

Random - 22-10-2010 at 11:09

Well, I looked, but citrazinic acid looks like citric acid to me, nothing very special

Nicodem - 23-10-2010 at 00:41

Quote: Originally posted by Random

Well, I looked, but citrazinic acid looks like citric acid to me, nothing very special

If that is the case then you should perhaps change your hobby and find a better pastime more suitable to your needs.

Random - 25-10-2010 at 10:25

This hobby is interesting and I am not changing it, I just wanted to know if there were some other things to do with it..

Edit:

On BromicAcid's page I saw that citric acid can precipitate powdered nickel from it's water soluble salts:

Quote:

Nickel powder can be formed in a number of ways, most notably by the reduction of a soluble nickel salt in an aqueous medium by zinc powder or citric acid. Additionally it can be formed as is shown at left by the decomposition of nickel oxalate formed by the displacement reaction between sodium oxalate and a soluble nickel salt.

Is this true and can I precipitate some other metals with citric acid from their water soluble salts too like zinc?

[Edited on 25-10-2010 by Random]

Random - 28-2-2011 at 07:39

I now got urea and learned actually what can be done with citrazinic.

I want to do this reaction:

citric acid + urea --heat--> citrazinic acid --hoffman degradation--> isonicotinic acid --decarboxylation--> pyridine

I would like to perform it on test tube scale, just to see how the preparation is possible and also to see how pyridine can smell bad

Also I would like to learn some practical chemistry with that too.

Now, does someone know what should I do, how much urea to use and citric acid? If I would do it on test tube scale using candle and 2 grams of each substance, how long would I need to heat it? Because citric acid could decompose.

UnintentionalChaos - 28-2-2011 at 07:59

Quote: Originally posted by Random

I now got urea and learned actually what can be done with citrazinic.

I want to do this reaction:

citric acid + urea --heat--> citrazinic acid --hoffman degradation--> isonicotinic acid --decarboxylation--> pyridine

I would like to perform it on test tube scale, just to see how the preparation is possible and also to see how pyridine can smell bad

Citrazinic acid is actually 2,6-dihydroxy-4-pyridinecarboxylic acid. Hofmann rearrangement on citrazinic acid would do nothing (although the nitrogen is formally an imide so maybe something would happen to the ring). Hofmann rearrangement of the citrizinamide would give 2,6-dihydroxy-4-aminopyridine. The hydroxyls will basically be impossible to remove just like you'd be hard pressed to turn phenol back to benzene.

Random - 28-2-2011 at 08:19

Oh yes, I forgot that to make isonicotinic I need POCl3 and then reduce that with hydrazine.

Also maybe by decarboxylation of citrazinic acid we could get 2,6-Dihydroxypyridine. By the way, what would we get by decarboxylation of citric acid? Maybe we could make some other organic compounds from 2,6-Dihydroxypyridine.

But anyway, I want to make citrazinic acid, because I know I will be able to do something with it.

Chordate - 28-2-2011 at 10:40

This is a bit late, but citric acid is also an alternative to hydrazine as a reducing agent for graphite oxide. If you want to make some diy graphene paper or try and jury-rig an old inkjet to make printable circuits.

See:

"Environmentally friendly approaches toward the mass production of processable graphene from graphite oxide"

J. I. Paredes, S. Villar-Rodil, M. J. Fernández-Merino, L. Guardia, A. Martínez-Alonso and J. M. D. Tascón

J. Mater. Chem., 2011, 21, 298-306

Random - 27-7-2011 at 03:47

I did the experiment yesterday. Into the test tube I put equal amounts of citric acid and urea and then I heated that test tube using candle. Soon as it melted the mixture started producing gas, after some time I observed very weak blue color in the previously colorless melt. Then I left it heat even more as It turned to blood red-brown melt that If I remember correctly became solid. When it cooled, half of the test tube was filled with solid sticky mass that on the sides was green, while inside was blood red-brown color. I was slowly filling the test tube with NaHCO3 solution and it dissolved the residue slowly (some gas, maybe CO2 was also slowly produced). Then I wanted to precipitate that with vinegar, but with excess vinegar added the solution was already 150mL so it looks citrazinic acid was dissolved. It was left to evaporate in hope some citrazinic acid will precipitate, further results will be reported.

Kamikaza - 27-7-2011 at 12:05

I did the experiment today, and these were my findings:

First I mixed an equal amount of ureum and citric acid. This was heated without solvent on a hotplate, and it slowly dissolved (probably in the water of crystallisation). It slowly turned yellow, then orange, then red, then black. This probably only is because of the increase of concetration of citrazanic acid, as it is quite a powerfull yellow dye. When it was dilluted, it became yellow again. When acid was added, it turned slighty more yellow. When natrium hydroxide was added a white precipitate was formed. This was quite unexpected as wikipedia stated that citrazinic acid should precipitate in acid

. Then I filtered the solution, and boiled it down. Now I have some blood red crystals. So it looks like the ureum citric acid syntheses was quite succesfull. I don't have any solid information about the yields, because my scale is broken, but it doesn't look to bad

Random - 27-7-2011 at 14:46

Strange, what could be that white precipitate? Those blood red crystals could be citrazinic acid, though, I am not sure what is that we are making: Citrazinic acid, citrazinamide or ammonium citrazinate? I will see tomorrow if my solution will make some crystals. By the way, what is the acid you are using?

distorto - 27-7-2011 at 19:36

Citric acid is good reducing agent for gold nanoparticle preparation.

It's mild, controllable reducing agent which allows the synthesis under room temperature.

White Yeti - 29-7-2011 at 05:22

I'm surprised no one showed up at your door to ask what you were going to use that citric acid for.
Citric acid is used to catalyse the peroxidation of acetone. As you may know, acetone peroxide is a high explosive, used by terrorists to blow things up. So whatever you do, do not buy any acetone or peroxide because then they will definitely show up at your door.

ScienceSquirrel - 29-7-2011 at 05:34

Quote: Originally posted by White Yeti

I'm surprised no one showed up at your door to ask what you were going to use that citric acid for.
Citric acid is used to catalyse the peroxidation of acetone. As you may know, acetone peroxide is a high explosive, used by terrorists to blow things up. So whatever you do, do not buy any acetone or peroxide because then they will definitely show up at your door.

Citric acid is sold by the kilogram for making bath fizzies. Acetone can be bought by the litre at your local fibreglass shop and 30% hydrogen peroxide is at your local health shop.
All three compounds have legitimate common large scale uses so banning or controlling them is not very likely or possible and as for tracking purchases the police would do nothing else if they had to watch them.

Random - 18-7-2012 at 11:40

As for my citrazinic experiment, nothing was accomplished.

The dark brown sticky mass didn't evaporate, it just smelled somewhat bad.

Flourescence wasn't observed, it was hard to dillute it with water, not too soluble.

On the outside it was loking green, but inside the test tube was all dark brown. Not sure if I cooked it too much with the candle. Basically, it's harder to make it than it sounds. The compound didn't have those properties described by the paper provided here at all. Further reactions just didn't happen. Something tells me it was just burnt citric acid.

Random - 9-11-2012 at 21:11

2nd experiment

put 2x urea as much as citric acid
heated it for only short time
got gellatinous yellow transparent solid at the bottom
dissolved it in water
separated into 2 test tubes
added vinegar into one and NaHCO3 into another
no precipitate was seen :mad:

i am starting to think that its all bullshit what is written there :mad:

Did anyone made any citrazinic acid? I mean precipitated it from solution?
Because I can't seem to precipitate anything at all.

Nicodem - 10-11-2012 at 03:32

Quote: Originally posted by Random

i am starting to think that its all bullshit what is written there :mad:

Did anyone made any citrazinic acid?

You think something is bullshit after you made no effort to reproduce it? :mad:

There are several authors describing the procedures for preparing citrazinic acid and yet you ask if anyone made any? At least have some respect for their work, even when for whatever reason you don't want to follow the procedures they developed.

Random - 10-11-2012 at 18:22

Quote: Originally posted by Nicodem

Quote: Originally posted by Random

i am starting to think that its all bullshit what is written there :mad:

Did anyone made any citrazinic acid?

You think something is bullshit after you made no effort to reproduce it? :mad:

Sorry I was just dissapointed in results as I tried this experiment more than once...

I will try it again in more controlled conditions.

By the way, this is the picture of citrazinic acid I found on the internet:

This is the colour I obtained, but as a gellatinous solid. SO either I was pretty close, obtained too small amount of acid to be isolated or gellatinous solid was just decomposed citric acid along with very small amount of citrazinic acid.

What I can say that last time I heated it for way too long time and I obtained black tar which I thought It was citrazinic acid.

If I manage to make it, I will gladly post the pictures.

aliced25 - 28-4-2013 at 03:06

Check this paper out, then look at what you are doing.

Quote:

In
order to satisfy ourselves as to whether citramic derivatives would condense under similar circumstances, we heated (a) citramide and (b) the mixture of citramic acids which is left as mother liquor in the preparation of citramide, each with ammonia, of 0.880 at 120-130".

In each case, a good yield of citrazinic acid was obtained ; the absence of citrazinamide, which might have been expected to be produced, is indicated by the analyses :-

(a.) 0.1146 gram of substance gave 9.6 C.C. N at 759 mm. and 21".
(p.) 0.1611 ,, 79 12.7 ,, 759 ,, 19.5".

Calculated for Pound.

C6H5N04. (a*> (P.)
N .. .. .. .... 9-03 9.5 9.08

Similarly, methyl citrate was found to yield citrazinic acid when heated with ammonia in a sealed tube ; the yield was 33 per cent. of the citric salt taken.

LXXXIV.—Anhydro-derivatives of citric and aconitic acids
T. H. Easterfield and W. J. Sell
J. Chem. Soc., Trans., 1892,61, 1003-1012
DOI: 10.1039/CT8926101003

But if methyl citrate heated with ammonia gives citrazinic acid, then the anhydride/acid chlorides are presumably overkill. Try boric acid, ammonia and the acid (http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=v81...).

The paper is attached on an earlier page of this thread. I also read that in MW processing of polymeric gel precursors, they try to keep the ethylene glycol/citric acid temp below about 170C as the citric acid dehydrates to aconitic acid and precipitates. Could be useful.

[Edited on 28-4-2013 by aliced25]

Fantasma4500 - 28-4-2013 at 13:15

well it can be used to make sucrose into glucose (glucose-glucose)
more sirupish
i guess this is good for rocketfuel as you often add abit of sirup to it

i did this by heating about... what.. 50g with 0.1g citric acid and abit of water in a beaker
think the actual ratio is ~450g to 1g citric acid
it will become golden and slurry ish, so apart from that it tastes good there is actual energetic uses of this and probably a few for chemistry purposes, but probably not many you couldnt use normal sugar for

aliced25 - 24-5-2013 at 20:35

According to this article (http://pubs.rsc.org/en/content/articlelanding/1913/an/an9133...), oxidize it to acetonedicarboxylic acid with permanganate. That acid isn't stable it needs to be esterified, preferably with methanol (it might come in handy someday). Interestingly, that isn't the only reference I've seen to Acetonedicarboxylic acid being made with permanganate - despite the usual preparation requiring fuming H2SO4 (http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1...) - the simpler, OTC route seems to have been ignored.

Or react it with bromine water to form pentabromoacetone (http://www.jbc.org/content/113/1/235.full.pdf+html?sid=1ea03... or this one http://www.jbc.org/content/156/1/33.full.pdf), I'd suggest by pretty much the same mechanism as it forms pentachloroacetone (as suggested up-thread):

Quote:

On Stahre's Reaction for Citric Acid. A. Wohlk. (Zeit. anal. them., 1902, xli., 77-100.)-The sensitive reaction for citric acid discovered by Stahre (Nordisk Farm. Tidsskrift, 1895, ii., 141) is based upon the fact that on oxidizing citric acid with potassium permanganate and adding bromine a white precipitate insoluble in ether is obtained. Stahre concluded that in this reaction the citric acid was oxidized to acetone, which was converted by the bromine into a bromacetone.

In applying the test when less than 5 milligrammes of citric acid are present, the acid is dissolved in 2 C.C. of water, and heated to 30" C. after the addition of 2 to 4 drops of & permanganate solution. If any slight precipitation of manganese peroxide occur, 1 or 2 drops of a, 4 per cent. solution of ammonium oxalate and about 1 C.C. of 10 per cent. sulphuric acid are introduced to clear the liquid. On now adding 2 drops of bromine water a distinct turbidity is produced.

When more than 5 milligrammes of citric acid are present the solution in 2 C.C. of water is treated with 5 drops of the permanganate solution, heated to 30" to 40" C., cooled, and mixed with 1 C.C. of dilute sulphuric acid. Should any precipitate be formed it can be removed by the addition of a little ammonium oxalate. Bromine water then added drop by drop gives a precipitate of extremely fine needles of pentabromacetone.

Stahre's reaction is obtained not only with pure solutions of citric acid and its salts, but also in the presence of other organic acids precipitated by calcium, such as tartaric, oxalic, malic acids, or inorganic acids, such as sulphuric and phosphoric acids. In such cases, however, more permanganate must be used, and it is best to make the test on a hot solution. Organic acids that react with bromine must obviously be removed.

The author confirms the statements of Henkel, Scheibe, and others as to the presence of citric acid as a normal constituent of milk, He has separated a compound which he has identified as citric acid by Stahre's reaction and other tests. (The Analyst, 1902, vol.27, pp.196-197: http://lib3.dss.go.th/fulltext/Journal/analyst/Analyst1901-1...)

Those olden day chemists - inventive bastards really, see what comes of not having consistent lab supplies? Pretty much what we have to deal with actually. Good to know that the reaction is named, Stahre's Reaction, well there you go

[Edited on 25-5-2013 by aliced25]