Sciencemadness Discussion Board - Decarboxylation of Glycine to Methylamine?!

Decarboxylation of Glycine to Methylamine?!

DIBALL - 15-3-2018 at 09:32

Well in theory it should be possible, or not?

I tried it with 1g of Glycine in Propylenglycol (not really soluble when cold) and 1g of Cyclohexanone and refluxed it for an hour. In my theory it should be released as a freebase gas, but nothing happened. The solution turned orange (probably due to the high temperature) and not more.
I know that alcohols dissolve Methylamine pretty well (30% by weight in Ethanol), but I couldn´t smell any of this stuff anyway.

Just for fun I tried heating the Glycine with basic copper carbonate (like in the Niacin to Pyridine synthesis), but as I expected nothing happened.

Was the temperature too low (in the first experiment) or anything else wrong? Could this even work? I mean decarboxylations of Pyridine and Tryptophan for example have quite big molecules and Glycine is small...

Chemi Pharma - 15-3-2018 at 09:49

@Diball, aminoacids are generaly decarboxylated in presence of ketones at reflux, withouth propylenglycol as a solvent, as far I know. May be that's the problem.

Try to mix glycine with acetophenone, knowed as a ketone that's will give you better yields and DMSO as a solvent if you really think that you need a solvent to mix them, refluxing at 150ºC.

read this thread about the decarboxylation of aminoacids. May be it enlighten your ideas:

http://www.sciencemadness.org/talk/viewthread.php?tid=74727&...

DIBALL - 15-3-2018 at 10:12

As far as I know, the solvent is there to archive high temperatures and Propylenglycol has a BP of 188°C, also I added Cyclohexanone, which should be the catalyst. Acetone should work as well. I used this as inspiration: https://erowid.org/archive/rhodium/chemistry/tryptophan.html
Don´t think the solvent is the problem, though it is not optimal.

[Edited on 15-3-2018 by DIBALL]

Chemi Pharma - 15-3-2018 at 10:22

But I think you're with a solvent matter. Propylenglycol don't dissolves well glycine and I think it's interfering with the ketone catalisys of glycine decarboxilation. Also, propylenglycol can absorbe all methylamine and carbon dioxide the reaction produces and may be it's the cause you're sniffing nothing smelling from the reaction vessel.

How much propylenglycol are you using in therms of mol equivalent?

DIBALL - 15-3-2018 at 10:32

I used way to much of PG. If think it was around 20-30mL. But since it has such a characteristic smell and the temperatures were really high, I thought maybe a bit would escape. Maybe I should try with a different solvent. Do you know the exact process of this decarboxylation? I honestly don´t get it, what difference a ketone makes in this reaction, only that it might produce an intermediate with the amine.

LearnedAmateur - 15-3-2018 at 10:37

What was your exact procedure, starting from glycine? There may be clues in what steps you took. I’ve never tried a decarboxylation myself but I and others may be able to offer some insight into what went wrong..

Chemi Pharma - 15-3-2018 at 10:42

I could answer your question here in this space. But it would be a tiring answer.

Again I tightly recommend you to use DMSO instead propylenglycol.

You'd better read the thread I suggest you to read before:

http://www.sciencemadness.org/talk/viewthread.php?tid=74727&...

If you are just interested on the mechanism of aminoacids decarboxilation mediated by ketones I'm attaching the paper I attached there again to you. Read it:

Attachment: Decarboxylation by heat of a-Amino-acids in the Presence of Ketones.PDF (642kB)
This file has been downloaded 688 times

[Edited on 15-3-2018 by Chemi Pharma]

Shiva_Inorganic - 15-3-2018 at 10:56

I had tried this before. It decomposes into Methylamine and Carbon dioxide when heated with Soda lime.

H2NCH2COOH ----> CH3NH2 + CO2

But not sure how to separate Methylamine from carbon dioxide. Still thinking of it.

DIBALL - 15-3-2018 at 11:00

Quote: Originally posted by LearnedAmateur

What was your exact procedure, starting from glycine?

1g of Glycine was dissolved in 10mL of PG. Since it didn´t dissolve properly, 20mL of PG were added and around half of it went into solution. 1mL of Cyclohexanone was added and refluxed for 1h.

@Chemi Pharma
That paper looks great! Thanks for that!
So its a Schiffs base which is formed... that should mean, that the reaction is water sensitive? Didn´t dry any of the reagents or solvents...
Well I will try it again with DMSO or acetophenone

Quote: Originally posted by Shiva_Inorganic

I had tried this before. It decomposes into Methylamine and Carbon dioxide when heated with Soda lime.

H2NCH2COOH ----> CH3NH2 + CO2

But not sure how to separate Methylamine from carbon dioxide. Still thinking of it.

What did you exactly do? Methylamine could be bubbled in a HCl solution. Sounds interesting

[Edited on 15-3-2018 by DIBALL]

DraconicAcid - 15-3-2018 at 11:01

Quote: Originally posted by Shiva_Inorganic

Seriously? Carbon dioxide can be easily absorbed by solid NaOH. Or the methylamine can be absorbed by strong acid, then released by addition of strong base.

Shiva_Inorganic - 15-3-2018 at 11:05

I did not bubble it through HCl as I wanted it as a free base. But, I bubbled it through water and the liberating gas turns wet red litmus blue. It has a disagreeable odour. I tried to ignite it but it did not burn probably due to the presence of CO2.

[Edited on 15-3-2018 by Shiva_Inorganic]

Chemi Pharma - 15-3-2018 at 11:09

Quote: Originally posted by DIBALL

@Chemi Pharma
That paper looks great! Thanks for that!
So its a Schiffs base which is formed... that should mean, that the reaction is water sensitive? Didn´t dry any of the reagents or solvents...
Well I will try it again with DMSO or acetophenone

No absolutely water sensitive, cause the subsequent hydrolisys of the Schiffs base requires an acidic or basic medium. I think the reagents don't need to be absolutely dry. The paper didn't say that. However it's what I think, I don't have any study to base this.

Shiva_Inorganic - 15-3-2018 at 11:13

Yeah good idea. Methylamine can be used as a scrubber to absorb various acidic gases. As you rightly pointed out, CO2 can be removed by passing it over solid NaOH. I need to find a proper apparatus to try it though.

Shiva_Inorganic - 15-3-2018 at 11:19

Unlike other chemistry youtube channels, I do not have many apparatus. But, I have a fair number of chemicals though. Using them, I have been posting videos about some rare chemicals like Sodium phosphide, Nitrosyl chloride, Nitrosyl bromide etc..

LearnedAmateur - 15-3-2018 at 11:22

Quote: Originally posted by DIBALL

Oh right, I would’ve thought that sodium hydroxide would’ve been involved somewhere along the line. When I think decarboxylation, I imagine that CO2 is removed as a carbonate like Shiva mentioned during a dry distillation. R-COONa + NaOH + heat -> Na2CO3 + 2 R-H. Maybe try this method out? If you don’t have access to NaOH then it can be produced from the carbonate by heating. Acidifying the methylamine after distillation will help with workup because it can be re/crystallised, the CO2 and subsequent carbonic acid becomes a non-issue as it is displaced by e.g. HCl, and the salt is a convenient form to store. Maybe I will give this sort of thing a go, I believe I have some lysine lying around somewhere so I can make 1,5-pentanediamine.

[Edited on 15-3-2018 by LearnedAmateur]

DIBALL - 15-3-2018 at 11:38

Quote: Originally posted by Chemi Pharma

[
No absolutely water sensitive, cause the subsequent hydrolisys of the Schiffs base requires an acidic or basic medium. I think the reagents don't need to be absolutely dry. The paper didn't say that. However it's what I think, I don't have any study to base this.

Okay, I was already wondering, why no synthesis on erowid mentions a dry solvent. Dry solvent it is then!

@Shiva_Inorganic
Can you explain how you did your reaction and to what temperature you heated it? You could bubble the freebase into ethanol or something else which dissolves it quite well.

@LearnedAmateur
NaOH is available. But it sounds almost to easy. Do you have a reference?

LearnedAmateur - 15-3-2018 at 11:40

Of course, and it is so easy that’s why I thought it was the route you were trying to accomplish!

https://www.chemguide.co.uk/organicprops/acids/decarbox.html

Chemi Pharma - 15-3-2018 at 11:40

Quote: Originally posted by LearnedAmateur

I think a misunderstood are happening here. The goal is to decarboxylate an alfa aminoacid to an amine with a less carbon and not decarboxylate a carboxylic acid or it's salt to an alkane with a less carbon. Isn't it?

LearnedAmateur - 15-3-2018 at 11:46

Decarboxylation removes one carbon atom as, effectively, CO2 which is taken up by the hydroxide to form the carbonate. If you had a standard carboxylic acid like acetic acid, methane would be produced - what is happening with glycine is analogous, just replace a H on the adjacent carbon with NH2, hence you get methylamine. Also I made a mistake in the last part which has been corrected.

[Edited on 15-3-2018 by LearnedAmateur]

Shiva_Inorganic - 15-3-2018 at 11:49

Nope Chemi. Decarboxylation of amino acid is one of the methods to prepare primary amines. You can even use Barium hydroxide (anhydrous) to prepare Methylamine. Glycine (aminoacetic acid) decomposes in the similar way when you heated with a strong base.

Shiva_Inorganic - 15-3-2018 at 11:54

DIBALL, not sure about the temperature. If you have the burner, heat it for 2-3 mins. I heated the mixture until it turns black for Methane preparation and it worked wonderfully well.

https://www.youtube.com/watch?v=tdFLvCTBJ0o

[Edited on 15-3-2018 by Shiva_Inorganic]

Chemi Pharma - 15-3-2018 at 12:23

Quote: Originally posted by LearnedAmateur

Decarboxylation removes one carbon atom as, effectively, CO2 which is taken up by the hydroxide to form the carbonate. If you had a standard carboxylic acid like acetic acid, methane would be produced - what is happening with glycine is analogous, just replace a H on the adjacent carbon with NH2, hence you get methylamine. Also I made a mistake in the last part which has been corrected.

Do you have I paper or a study to base this? I never heard about decarboxylating amino acids to amines with one less carbon with alkaline base before.

If so could you post it here? I will enjoy to read about it.

[Edited on 15-3-2018 by Chemi Pharma]

Chemi Pharma - 15-3-2018 at 12:38

Quote: Originally posted by Shiva_Inorganic

Nope Chemi. Decarboxylation of amino acid is one of the methods to prepare primary amines. You can even use Barium hydroxide (anhydrous) to prepare Methylamine. Glycine (aminoacetic acid) decomposes in the similar way when you heated with a strong base.

Do you have some paper or study to base this? Is the same question I made to @LearnedAmateur. If so I will enjoy to see that and read about this strange theory behind this kind of reaction. Post it here please.

[Edited on 15-3-2018 by Chemi Pharma]

DIBALL - 15-3-2018 at 12:58

Just mixed NaOH and Glycine in a test tube and after heating there was a reaction that released some gas, but the products looked like water and some solid. More heating released ammonia gas...

@Shiva_Inorganic
Nice Youtube channel!

Boffis - 15-3-2018 at 13:23

@ Diball; when you heat glycine with glycols you get cyclitisation to to piperazine-2,5-dione. Alanine yields the 3,6-dimethyl analog. Once formed these compounds cannot form a Schiff base type condnsation product so I suspect that once formed these compompounds resist the effects of a ketone. The formation of these piperazines should occur with any alpha amino acid but in practice only the simplest of the amino acid undergo this type of reaction as far as I am aware.

I think that shive_inorganic is onto something with his sodalime degradation. Has anyone tried heating calcium glycinate and calcium oxide to decomposition? The idea of the extra calcium oxide is to remove an extra CO2 and reduce the formation of C3 compounds (as in the case of acetone from calcium acetate).

Diball, in your last post how did you determine that the gas released was ammonia? Methylamine smells much like ammonia.

DIBALL - 15-3-2018 at 13:57

Quote: Originally posted by Boffis

@ Diball; when you heat glycine with glycols you get cyclitisation to to piperazine-2,5-dione. Alanine yields the 3,6-dimethyl analog. Once formed these compounds cannot form a Schiff base type condnsation product so I suspect that once formed these compompounds resist the effects of a ketone. The formation of these piperazines should occur with any alpha amino acid but in practice only the simplest of the amino acid undergo this type of reaction as far as I am aware.

I think that shive_inorganic is onto something with his sodalime degradation. Has anyone tried heating calcium glycinate and calcium oxide to decomposition? The idea of the extra calcium oxide is to remove an extra CO2 and reduce the formation of C3 compounds (as in the case of acetone from calcium acetate).

Diball, in your last post how did you determine that the gas released was ammonia? Methylamine smells much like ammonia.

Alright, so my first reaction failed because I made piperazine-2,5-dione. That makes sense!

I remember the smell of methylamine from my last formaldehyde/ammonium chloride synthesis as a substance, that smells like fishy cat piss. This one was smelling like ammonia. But now that I think about it, it would make more sense for the glycine to release MeNH2 instead of ammonia!
Is there a way to test, if it is actually MeNH2 and not ammonia?

The calcium route sounds interesting. Magnesium should work as well?

[Edited on 16-3-2018 by DIBALL]

Chemi Pharma - 15-3-2018 at 23:51

I suspect this kind of decarboxylation of glycine with sodalime will evolute to the decomposition of any methylamine generated in situ to HCN, methane and ammonia, like said in the paper I attached.

So, I think these concurrent reactions take place, based on what I read in "The Hive" on the NET, and what the paper say:

NH2CH2COOH + 2 NaOH --> Na2CO3 + H2O + CH3NH2

CH3NH2 ---> HCN + 2 H2

HCN + NaOH --> NaCN + H2O

CH3NH2 + H2 --> CH4 + NH3

Overall reaction:
3 NH2CH2COOH + 7 NaOH --> 3 Na2CO3 + NaCN + 4 H2O + 2 CH4 + 2 NH3

Maybe because this fact @Diball sniffed only ammonia smell instead methylamine, while heating glycine and sodalime in the test tube.

Attachment: thermal decomposition of methylamine.doc (154kB)
This file has been downloaded 484 times

[Edited on 16-3-2018 by Chemi Pharma]

Melgar - 16-3-2018 at 00:35

No, propylene glycol is not your problem. It works just fine as a solvent for decarboxylation using an enone catalyst. Your issue seems to be misreading a single vowel in the writeup; you need cyclohexenone, which is not very easy at all to find. What you probably have is the much more common cyclohexanone. But all is not lost. Spearmint oil contains carvone, which is a suitable enone for this decarboxylation. However, this reaction may not work with glycine, as I've never tried it. It will work with the higher MW ones though.

Pumukli - 16-3-2018 at 07:43

"@Diball sniffed only ammonia smell instead methylamine"

Can anyone tell the difference by smell between NH3 and methylamine?

When I smelled dimethylamine for my nose it was 100% as if it was ammonia. I suspect that the difference between methylamine and ammonia smell is even smaller if any.

Also, my gut feeling is that the process:

CH3NH2 ----> HCN + 2 H2

is not particularly favoured thermodynamically. Much less under the circumstances of decarboxylation. Maybe at higher temperatures it can be significant.

Edit: yepp, first I wrote my posting, then I downloaded your reference. It definitely talks about HIGH temperatures!
When will you reach 500-550 C (not to mention 1200) during a decarboxylation, especially in a test tube?

[Edited on 16-3-2018 by Pumukli]

Chemi Pharma - 16-3-2018 at 08:22

I had sniffed ammonia vapours and also methylamine vapours many times during some synthesis. The two smells are completely different I can assevere you this @Pumukli.

The paper say what happens at 500ºC with methylamine alone, that decomposes in HCN, methane and ammonia. I have my doubts if sodalime could catalyze this reaction in much lower temperatures, like 250ºC.

Anyway, I challenge anyone here to prove I'm wrong bringing references that Glycine can produces reliable quantities of methylamine by thermal decarboxylation with alkalis or earth-alkalines oxides.

Glycine is an aminoacid, the amino group undergoes unstable during a high temperature thermal decarboxylation, finishing to evolving like an ammonia gas from the reaction vessel. This is the reason aminoacids decarboxylation is usually do by schiff base pyrolisys (at much lower temperatures) or hydrolisys, formed between their reaction with ketones. I never heard about this kind of decarboxylation and never saw it in any organic chemistry book I've read.

No way aminoacids decarboxylate the same way carboxylic acids does with sodalime or equivalent and I wonder seeing references that proves this theory.

[Edited on 16-3-2018 by Chemi Pharma]

LearnedAmateur - 16-3-2018 at 08:39

I don’t think either can be readily distinguished by smell due to how similar they are, it would be like trying to differentiate formic and acetic acid in the same way, both smell like vinegar so it’s pretty much impossible. Plus, the human senses aren’t exactly prime scientific tools, what one person may experience could be different from others; personally I find that ammonia is a ‘fishy cat piss’ smell as described for methylamine, plus -CH3 is a fairly inert group so it wouldn’t do much to modify the base odour.

That’s what I was thinking, doesn’t decarboxylation occur around or below 200-300C? Can’t find any references to specific temperatures but I’m sure that it wouldn’t need to be as high as the decomposition temperature of methylamine. Plus, since it’s being removed as a gas, yields would only be slightly affected - of course there will be a little contamination if you take a Boltzmann distribution into consideration, but distilling off methylamine would take it to lower temperature regions so decomposition is retarded. Definitely not a case where the gas is forcefully contained in a vessel which is at the required temperatures for significant conversion.

Chemi Pharma - 16-3-2018 at 08:57

I agree that olfact is not the most reliable sense the human body have. I can't describe that, but the difference between ammonia and methylamine smell, FOR ME, is quite singular. The same between formic acid and acetic acid, The both, FOR ME, are unmistakable.

But I think it's overkill when you say: "... plus -CH3 is a fairly inert group so it wouldn’t do much to modify the base odour." Don't say this kind of thing man. Even one more atom linked to a molecule change everything, including the odour. Is like to claim methyl iodide has the same odour of iodine, cause is just a -CH3 group attached, isn't it?

I will not discuss more, cause it's a waist of time and efforts. I just want references about the theory you claim to work. Until there I will keep my position.

Pumukli - 16-3-2018 at 09:14

All right :-) Now I know that NH3 and MeNH2 smell the same. And I also know they are quite different in this regard. :-)

So it seems someone should test it (unless one can find a good reference.)

What would be the best (amateur friendly) method differentiating between NH3 and MeNH2? Some sort of precipitation? Making an amide and determining its melting point?

LearnedAmateur - 16-3-2018 at 09:32

It depends on the class of molecules, iodine (a halogen where I is in the 0 oxidation state) has VERY different properties to methyl iodide (a haloalkane with I in the -1 oxidation state) - Cl2 and HCl smell nothing alike because they’re barely reminiscent of each other in terms of properties, even though they both contain chlorine atoms. On the other hand, both formic and acetic acid are homologous carboxylic acids, and methylamine/ammonia are homologous amines where the NH2 is the main group in question, and is responsible for the smell of ALL amines.

Anyway, I can’t find a reference to the decarboxylation of a-amino acids using sodium hydroxide, but I did come across this equation which uses barium hydroxide instead. It comes from this webpage: https://chemistry.tutorvista.com/biochemistry/amino-acids.ht...

I still stand by what I say though, going off the reaction mechanism for decarboxylation.

14BC6360-E48B-48C4-B007-B2406AB26EA0.png - 3kB

Chemi Pharma - 16-3-2018 at 10:06

Still waiting for reliable references. :cool:

Come on, this equation is completely theoric. Everyone can write this and Tutorvista are not a worthy site of organic chemistry.

Try to find a research, a study or a reference inside a reliable organic chemistry book. I spent two hours at google searching for that and found nothing. If you get you deserve my congratulations man.

LearnedAmateur - 16-3-2018 at 10:29

Believe me, if I could find a reference then I would’ve jumped on it immediately, it’s just annoying because I can find alternate synthesis conditions (for example using n-bromosuccinimide: https://pubs.acs.org/doi/abs/10.1021/jo00208a012?journalCode...) but there really isn’t anything much on the thermal decarboxylation of alpha amino acids, especially Na salts of such. All I can go off is the general decarboxylation reaction which I’ve outlined multiple times, but that unfortunately doesn’t include any possible reactions involving the anime or C-N bond, even if none occur.

Since we can’t find any laboratory publications, our best bet will be for one of us to try it. For that to occur though we need to devise a conclusive test for methylamine that doesn’t involve reaction at the amine. Detection of HCN by MeNH2 decomposition may be one route, but is exceedingly dangerous if we’re dealing with hundreds-milligram scales.

According to ChemicalBook, MeNH3Cl melts at ~232C whereas NH3Cl melts/decomposes at ~340 so that’s a good test to focus on. Should tell us whether the major amine produced is methylamine or ammonia, if someone wants to perform the experiment for the amateur community. Won’t take more than bubbling the pyrolysis products of sodium glycinate/NaOH through hydrochloric acid then collecting the crystals for MPA; I’d try it myself but a), my clamps are broken so I can’t do a distillation, and b) I don’t have any glycine.

Pumukli - 16-3-2018 at 11:41

I would give it a go.

My plan is roughly: put a few NaOH beads into a mortar, put some glycine powder in and mix (and homogenize, pulverize) them quickly, before they liquify much. Then put a gram or so from this mixture into a test tube and heat it above a flame (or heat gun) and see what (and how) happens. Then smell the exit-gas (or find my old Nessler's reagent and test the color change.)

If the thing really reeks of ammonia or an amine then I would try it on a bigger scale in a 100ml flask (or something like that) and would distill off the amine into cold water.

Then we were back to stage 1: should find a simple, reliable, available route for identification. As I'm mostly into organic chemistry I thought of acylating the amine with something and determining the properties of the resulted amide. Unfortunately my m.p. meter is non-functioning at the moment but could be brought back to life in a few days. (needs oil).

LearnedAmateur - 16-3-2018 at 12:18

If you have access to chloroform and potassium hydroxide, the carbylamine reaction is another option for detection. Works with any primary amine, and should be a prime test in this instance.

“In this reaction, the analyte is heated with alcoholic potassium hydroxide and chloroform. If a primary amine is present, the isocyanide (carbylamine) is formed which are foul smelling substances.”

R-NH2 + 3 KOH + CHCl3 -> R-(N+)(C-) + 3 KCl + 3 H2O

96A9C7F9-15CE-4174-B4D7-290B7B18C681.jpeg - 129kB

DIBALL - 16-3-2018 at 12:40

I just remembered, that Ammonium chloride is poorly soluble in ethanol, but Methylamine HCl is soluble. So it should be quite easy to distinct those two. If the gas is bubbled into HCl and the crystals are soluble in ethanol, it´s Methylamine. Maybe I will give this a try this weekend.

Pumukli - 16-3-2018 at 16:36

That's it, the carbylamine reaction!

I'll go that way. It is quick and can be done theoretically in a test tube.

MeNH2 should produce something stenchy.
NH3 should produce HCN in (alkaline) solution, so it would not have much smell. (And would not be lethal smelling it either.)

According to this:

http://www.sciencemadness.org/talk/viewthread.php?tid=6915

The presence of ammonia could be detected by the prussian blue test (via the formed cyanide) too.

Pumukli - 17-3-2018 at 00:33

Preliminary result:

We all know that preliminaries could have big mistakes, but here it goes anyway.

I put 5-6 NaOH grains into a test tube and with a spatula sprinkled them with some glycine powder. Then applied about 0.5 ml distilled water via an eye dropper into the tube. I caught the test tube with a smaller diameter flask clamp and heated above open (gas) flame. At first heated along the full length of the tube to prevent water condensation and reflux and cautiously heated the content at the bottom of the tube last. It quickly boiled and the glycine dissolved. As the water distilled off some sort of faint purplish discoloration of the melt could be noticed. When I removed the test tube from the flame and let it cool a bit the liquid melt quickly solidified.

Melted it again and soon started a reaction: the liquid was bubbling like boiling water but at a point the so far clear and translucent liquid became turbid (milky appearance) and I think started releasing CO2. I base this statement on the different appearance of the bubbles: the whole mass was full of small gass bubbles and it seemed as if I poured acid on an alkaly carbonate. At the same time I smelled the gasses from the test tube and there was the unmistakeable amine (or ammonia) stench. So far so good, decarboxylation seems to work.

Quickly cooled the test tube (did not want to loose all the amine/ammonia by overheating, contents quickly crystallized), dropped about 10 drops of chloroform into the tube and started heating it again. It quickly started to boil but another reaction also took place: the so far milky appearance of the mixture became yellowish. And the smell of the vapours changed: it definitely got some sort of nauseating stench. In the end the sharp amine stench disappeared but some sort of disgusting, burnt protein - like smell remained.

I assumed it as positive result for MeNC, although I never smelled that compound before.

I repeated the reaction with a few drops of Roundup as well. (You know, it contains isopropylamine salt of glyfosate.) I was curious how the carbylamine test would go.
It went like this:

A few drops of Roundup and 3 NaOH grains and a few drops of CHCl3 at the bottom of another test tube. Heated on flame.
At first distinct amine odour in the air. Then some sort of rection ensued: the mixture became turbid, chloroform started refluxing from the walls of the test tube and an even more disgusting stench developed than in the previous reaction. It was like burnt caramell or burnt coffee mixed with decomposing meat and lingered long in my throat. (for a few minutes.)

So carbylamine rection seems positive again, but I never smelled iPrNC before. But if we are after malodorous compounds with this test then I'm pretty sure I got there.

I will test the remnants in test tube No 1 later for cyanide as well.

Chemi Pharma - 17-3-2018 at 01:22

Quote: Originally posted by Pumukli

Melted it again and soon started a reaction: the liquid was bubbling like boiling water but at a point the so far clear and translucent liquid became turbid (milky appearance) and I think started releasing CO2. I base this statement on the different appearance of the bubbles: the whole mass was full of small gass bubbles and it seemed as if I poured acid on an alkaly carbonate. At the same time I smelled the gasses from the test tube and there was the unmistakeable amine (or ammonia) stench. So far so good, decarboxylation seems to work.

Quickly cooled the test tube (did not want to loose all the amine/ammonia by overheating, contents quickly crystallized), dropped about 10 drops of chloroform into the tube and started heating it again. It quickly started to boil but another reaction also took place: the so far milky appearance of the mixture became yellowish. And the smell of the vapours changed: it definitely got some sort of nauseating stench. In the end the sharp amine stench disappeared but some sort of disgusting, burnt protein - like smell remained.

I assumed it as positive result for MeNC, although I never smelled that compound before.

Well done @Pumukli, but I have to make some observations:

I- When you say CO2 are released from the test tube, may be the gas were methane (CH4), in my theory.

II - If the gas evoluted were CO2, it will react in situ with NaOH to form a carbonate and water. No bubbles would be visible. Think about it.

III - although methylamine are inflamable and ammonia not, in this case the test of an open flame wont work cause, in your theory CO2 and CH3NH2 will be released and this mixture will burn at a flame. In my theory NH3 and CH4 will be released and this mixture will be inflamable too, cause the methane.

IV - The carbylamine test isn't enough to distinguish NH3 and CH3NH2. It's a proper test for distinguish primary from secondary and terciary amines. But think about it. Ammonia is a kind of primary amine eihter and will form a isocyanide too with chloroform (hydrogen isocyanide), while CH3CH2 will form methyl isocyanide. According wikipedia, both have a desagreeable smell and the olfact couldn't distinguish one from another.

V - I agree with @Diball when he said the better test to distinguish one from another is the ethyl alcohol solubility of the chloride or chloridrate. This question have been already discussed here at sciencemadness. See this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=11293&...

Pumukli - 17-3-2018 at 04:16

Since then I tried carbylamine test on NH4Cl. I could only smell sharp ammonia stench, nothing rotting/burnt meat.

I also tried checking for cyanide in the water solutions of the remnants. (Acidification either by citric acid/hydrochloric acid then addition of FeSO4 solution.) It was negative in all cases. I mean I did not get prussian blue in any case. What I got is a clear yellow solution in case of NH4Cl and a blackish/browish precipitate from the amines/isocyanides which precipitate quickly dissolved in the excess of acidic reagent, giving the same clear solution as did NH4Cl.

Now I have to do the washing because I can't put a needle on my lab bench. I need tydiing up before going any further. :-)

(Unfortunately I don't have any cyanide handy to make a definite positive prussian blue test.)

Btw bubbling/CO2 evolution:
You are right, in the excess of alkali no CO2 bubbling should be noticeable! Oh my! :-) I correct myself: what I did observe was NOT CO2 evolution but either NH3 or MeNH2!
When I tried the test on NH4Cl it gave a very similar "fizzing" as NaOH freed the NH3. It bubbled like freshly opened soda water.

[Edited on 17-3-2018 by Pumukli]

Pumukli - 17-3-2018 at 14:05

Making methylamine from glycine
testing a hypothetical pathway

After the promising results of the preliminary tests I decided I'd do the decarboxylation on a bigger scale.

Into a 100 ml roundbottom flask I measured 20 g (0.266 mol) glycine. I dissolved 12 g NaOH (0.3 mol) in roughly 26-28 ml water in a 100 ml beaker with external cold water bath cooling. Poured the solution into the flask, dropped in two boiling stone pieces too.

Then attached a distilling cooler onto the flask with thermometer. Attached an „auxiliary collector” - a 50 ml pear shaped flask- to the end of the cooler. Attached a teflon tube to the vacuum-port of the cooler and put a glass filter tulip to the other end of the tube. The real collector was a 150 ml beaker with 52 g water and a teflon stir bar sitting in a plastic box of cold water on a magnetic stirrer. (It is a bit complicated to explain, especially when I try to translate in a hurry, but you will see on the photos what I'm talking about. This is my tried and reliably working setup for amine distillations.)

I put the distilling flask into a sand bath on a hotplate and started to distill off the water.
The temperature of the sand was around 325 C by the time the water started to distill. The cooler was cooled by air (aquarium air pump) and wet tissue papers placed on and around its body. At first it was a bit hard to condense effectively the water but later when the mixture became drier the cooling became easier.

After I distillied off some water I detached the auxiliary collector and measured the weight of collected water. (I repeated this measurement several times during the distillation.) After I collected more than 10 millilitres of water I put one drop of phenolphtalein into the auxiliary collector. It turned pink immediately. It was a bit surprising because I could not smell any ammonia or amine at this point. Maybe the fine NaOH mist from the bursting bubbles was washed down with the condensing water.

After 25 millilitres of water was distilled the appearance of the contents in the distilling flask changed. So far it was absolutely clear and translucent, at this point it became almost foamy as it boiled. The cooling became easier because less water was distilling now. Meanwhile the temperature of the sand bath reached 333 C.

At 27 millilitres water collected there was still no amine or ammonia, not even traces. There was some sort of faint and unpleasant (burnt?) smell but nothing serious. Sandbath at 341 C.

Around this point I changed the thermometer in the sand bath from the mercury/glass one to a type-K thermocouple/digital meter because the mercury thermometer was approaching the end of its scale (360 C). Of course it made all the previous readings uncomparable to the new ones. The new thermometer read 210 C at the spot in the sandbath where I could insert it in. :-) And around these crucial moments the power controller of my hotplate died! Now on I could only On/Off switch it at full throttle. :-) At 1300 W available power it is not easy to smoothly do it.
I forgot to turn it off for a few more seconds and the hot plate was glowing in red! :-) Fortunately the sand had substantial thermal inertia and the heating up was steady and smooth according to the thermometer.

By the time the sand bath reached 233 C (new meter!) I could collect 28 milliliters of water and the contents in the distilling flask became fairly dry. Almost no water was condensing back. Neither any amine smell could be detected to my surprise!

Around 250 C sand bath temperature I realized that something is collecting on the inside wall of the distilling flask. There were „water” droplets on the flask wall – but at this temperature they can't be water, they would boil up explosively! But no, these droplets just refluxed back from the wall and flew down in the mixture with almost no boiling. Of course it was not the hoped amine either!

I have to mention that NO apparent bubbles could be seen so far in the real collector during the distillation. I can safely say that no uncondensable ammonia/methylamine/methane/whatnot appeared in the gas so far! On the other hand the vapour thermometer registered exactly 100 C so far. Not more not less, exactly 100 C since the water started distilling.

At around 273 C sand bath temperature something changed in the flask: its content got a definite yellowish hue. At the same time something started to bubble into the real collector! I smelled the off gas and it was surely amin/ammonia! Now it is here! :-) The vapour thermometer quicly declined, registered 82 C in these moments.

And the not so exact thermal control ruined everything in the coming two minutes... Some sort of exotherm occured and filled with an interesting brick red and yellow foam the distilling flask. The foam started to spew off smoke and yellow liquid condensed in the auxiliary condenser (a few millilitres, maybe 5 or less). I turned off the heat, removed some sand from the sand bath to help cooling but it was too late. Tomorrow I will have to do the washing up again. :-)

I doubt this dry distillation could be tamed to a productive synthesis. It did produce some sort of amine, maybe only ammonia. Unfortunately the point of amine production and runaway is too close to one another. Tomorrow I'll look after the remnants and decide if I could do anything meaningful with the condensed products both in the auxiliary and the real collectors.

I may try it again with a reliably working thermal controller one day. Maybe that way one could balance on the fine line between amine/ammonia production and thermal runaway, though I'm a bit sceptical.

[Edited on 17-3-2018 by Pumukli]

Chemi Pharma - 17-3-2018 at 15:11

Nice pictures @Pumukli. Sorry about the frustration with your experiment.

I suggest you try again and after the water were all distilled, you substitute the cooler by a silicone hose before the reaction mix runaway start up with amine/ammonia evolution and bubble the gas into a flask with HCl in ethyl alcohol solution.

I think you can do it even with your broked hot plate, since you're using a sandbath. Just monitoring the temperature and take note to publish here.

If you got a white solid precipitated, even a tiny amount, the gas were ammonia and the ppt ammonium chloride. If nothing precipitates the gas were methylamine and the hydrochloride will remain in the solution.

Pumukli - 17-3-2018 at 23:47

ChemiPharma:

I use this complicated setup because I learned (of course the hard way) that the tubing (silicone or not) what I can buy here is attacked by the distilling amine vapours in a few minutes. It discolorates first then starts to release some sort of oily substance and contaminates the distilling amine. Hence the all-glass vapour path and the PTFE tube at the end. This way the distilled amine remains pure.

I'd rather avoid the runaway reaction at all cost. It makes a very contaminated end-product (what you can see in the last picture, that is thick white smoke in the final collector and filter tulip.) I suspect that in a runaway there would be all sort of crap and probably a complex mixture of various N-compounds which would make identification even more troublesome.

Very careful and slow heating MIGHT make possible to distill something fairly pure off of the mixture. For this I have to repair the power controller at first and have a full day free time to really slowly approach the sensitive thermal region.

Edit: duplicated pictures removed.

[Edited on 18-3-2018 by Pumukli]

EilOr - 18-3-2018 at 07:46

Quote: Originally posted by DIBALL

Well in theory it should be possible, or not?

I tried it with 1g of Glycine in Propylenglycol (not really soluble when cold) and 1g of Cyclohexanone and refluxed it for an hour...

As you've used such a high amount of catalyst you may have made the methylamine-cyclohexanone imine as a main product
Also I think PG, despite the high bp., is a very suboptimal solvent as it's too polar.

I would try to use Mentha spicata var.crispa essential oil (OTC spearmint oil, consists mostly of carvone) as in my experience it's one of the best catalysts for decarboxylation, even better than Cyclohexenone and a bottle can be had for 3-10€.

As solvent I would use good old genuine terpentuine oil as it has optimal boiling point, is known to be very high yielding at least with aromatic amino-acids, quite cheap and OTC, but Shellsol T (a good less smelling terpuintine-substitute for many reactions) and especially DMSO or DMF etc. should also work

I wonder if methylammoniumcarbonate would be a side product or maybe even the main-product, causing low yields.

Maybe you could use an aqueus copper solution to detect methylamine (forming colorful complexes)

[Edited on 18-3-2018 by EilOr]

DIBALL - 22-3-2018 at 15:39

Great job and pictures Pumukli! That brings us a good step closer!

I retried this a couple days ago:

5g of glycine and 10g of NaOH were dissolved in way too much water (40mL) and the water was distilled off in a heating mantle. A hose was attached, which lead to a flak, which was filled with a 15% HCl solution. When the water was driven off, the now solid NaOH/glycine mixture started to melt and very soon after, a rapid reaction occurred! While during the water distillation only a couple bubbles reached the HCl solution, now it was a vigorously bubbling. The NaOH/glycine solution became really foamy and yellowish and I had to take the flask off the heating mantle, because it was starting to get into the hose. After cooling, I evaporated off the HCl solution and tried to dissolve the remaining ammonium/amine chloride in acetone (ammonium chloride is soluble in it, methylamine not) but it didn´t dissolve. After filtering I added anhyd. ethanol and it dissolved quite well (which methylamine does, but ammonium chloride not). Then I recrystallized it.

Looks for me like it is indeed methylamine! Only thing that bothers me, is, that the crystals didn´t look like the ones of the methylamine I had before. Also it isn´t really hygroscopic. Well when I have my new thermometer I will determine the melting point and then we will see for sure!

Maybe we could try with Trimethylglycine as well, since it should be easier to tell apart from the ammonia.

@Melgar and EilOr
Indeed I have mixed it up with CyclohexEnone... If the other method doesn´t work, I will try it with peppermint oil.

zed - 27-3-2018 at 16:45

Ummm. Yeah. I've run this reaction, and it seems to work, sort of.

First. If you attempt to run this de-carboxylation, neat, on a bulk amount of glycine, it will fail. You will produce massive amounts of brown polymeric crud.

If you disperse finely divided glycine, in a large volume of clean sand, then slowly distill the mixture, you will accumulate a reasonable yield of what appears to be Methylamine/Methylamine Carbonate. Smells right, looks right.... But, don't trust it. Convert it to the hydrochloride, and recrystallize it, ala Vogel. The idea is to isolate individual molecules, via dispersion in sand... so they cannot auto-condense into crud. Though the product is colorless, it appears that it is a mixture, not pure Methylamine. Might be anything in there.

Myself, and my colleague, Dr. CrazyFingers, once ran this reaction fairly successfully. Crazyfingers, impetuous boy, ignored my warnings and attempted to use this material without further purification. Well, garbage in....Garbage out.

As designed, our reaction was more-or-less a pyrolysis. Just a distillation flask, full of sand and Glycine, in an old electric stove, with a hole cut in the side, to allow the side arm to exit.

As I said, it seemed to work fairly well, but a real workup would be required to confirm. At the time, I had other priorities.

LearnedAmateur - 28-3-2018 at 01:27

Didn’t think of that, probably because I haven’t tried it out, very useful info for anyone attempting this. Could you also use other refractory materials like alumina and magnesia to good success or is silica the best/only option? Just requesting info for others in the case that the aforementioned is on hand.

Pumukli - 28-3-2018 at 08:41

Seems to be a good idea.
Also, the note about not being pure product but a mixture of MeNH2 and others (I tend to think mostly ammonia).

In the benzene from benzoic acid (or what) thread they used fine metal mesh to improve heat conduction to avoid hotspots and achieve thorough even heating. Maybe it wouldn't hurt in this case either.

DIBALL - 28-3-2018 at 16:06

I tried to determine the melting point and some of it decomposed like Ammonium Chloride, so like Pumukli mentioned, it is probably a mix of Methylamine and Ammonia.
Looks to me that too much heat and NaOH is too "aggressive" and converts a lot to Ammonium Chloride.
I would like to try the "sand method". What was your sand/glycine ratio?
Also I might go back to the "peppermint" idea. Maybe it´s more selective for Methylamine.

zed - 28-3-2018 at 16:13

Well, what reaction path is being followed in this sand-decarboxylation is difficult to project. Perhaps SiO2 somehow catalyses the reaction.

Sometime in the past, I read a paper wherein water separation was used, along with a ketone, to form the imine in bulk, followed by higher temperature decarboxylation of the imino-acid.

Had the paper somewhere. Darned if I can find it.

Copper Chromite might be a good catalyst. Seems to do the trick fer decarboxylaing nicotinic acid, to pyridine.

[Edited on 29-3-2018 by zed]

Chemi Pharma - 29-3-2018 at 01:56

Seems that we're all concluding that glycine decarboxylation with a strong base and elevated temperatures like carboxylic acid does it's impracticable with aminoacids, to produce even a modest yield of methylamine, like I said.

If this was a viable method, off course someone already had found some paper, research or recipe about that somewhere. But it's not the case until now.

Better follow the ketone-imine (schiff base) decarboxylation way, method that's well covered by many research studies and even here, at sciencemadness. See this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=74727&...

[Edited on 29-3-2018 by Chemi Pharma]

zed - 29-3-2018 at 14:13

Time will tell. It should be noted, that the method you are currently espousing, was not widely known a generation or so... ago.

The idea of producing easy tryptamine or phenethylamine, was quite alien.

Over the last 40 to 50 years, practical approaches to decarboxylation of aminoacids evolved.

At the moment, known pathways are limited. Surely there are more to be discovered.

DIBALL - 30-3-2018 at 06:59

Quote: Originally posted by zed

Copper Chromite might be a good catalyst. Seems to do the trick fer decarboxylaing nicotinic acid, to pyridine.
[Edited on 29-3-2018 by zed]

NileRed did once a video on decarboxylating nicotinic acid to pyridine with basic copper carbonate. I tried this too with Glycerine, but nothing happened. Maybe the temperature was too low or heating it in dry form (and badly mixed) was a problem.

I´ll try the peppermint method next week. I can´t see why this shouldn´t work.

zed - 31-3-2018 at 15:15

I've seen those videos. Copper Carbonate works poorly. Copper Chromite works very well. Seems to me Doug's Lab has a nice procedure.

I mentioned this because Nicotinic Acid, seems structurally quite similar to the imino-acids we are attempting to decarboxylate.

Copper Chromite accomplishes this decarboxylation, at right about 100 C.. A much lower temperature than that employed in most procedures.

DIBALL - 17-4-2018 at 06:53

So, I have some updates and some things that I can´t figure out, so I hope you can help me.

A week ago I did the first decarboxylation:

I put 2g of glycine into 30mL of DMSO and 10 drops of the spearmint oil into a 100mL round bottom flask and connected it with a hose to a flask with diluted HCl solution. The glycine didn´t dissolve properly though.

When I started heating I noticed a little bubbling occurring at around 120 degree, which I thought was maybe the peppermint oil boiling, but then I saw, that it came from the undissolved glycine powder. Gas came over to the HCl solution. At the DMSO reflux temperature the bubbling got stronger and stayed constant. Since I didn´t used a reflux I stopped when the DMSO reached the hose. It was interesting to see, that the bubbling continued, even after I turn off the heat and it stopped, after all the undissolved glycine disappeared!

Then I boiled off the HCl solution, but in a moment, where I wasn´t watching, I burned it...

So I tried this again, but this time with less DSMO (20 mL) and 5g of glycine. Also I added a reflux condenser and switched to a phosphoric acid solution.
This time I noticed, that even without heating already a bit of gas came over! But it was a bit slower now, which I think was due to a lower DSMO amount. Then I realized that some crystals are forming in the condenser. I measured the temperature of the part of the condenser that wasn´t cooled and it was not the temperature at which glycine is boiling.
After some time the condenser was cloaked and a mini "explosion" occurred, where the rubber stopper jumped out of the flask. It was smelling like ammonia and reminded me of methylamine.

I stopped the reaction then and evaporated the H3PO4 solution and noticed, that it was reddish and stopped at about 5mL. Next I will see if cooling it will get me some crystals.

But I have the feeling, that there was some side reaction with the DSMO? I´ve read that it can methylate methylamine in acidic conditions, but might there be some reaction with the glycine? I mean the crystals in the condenser and the HCl and H3PO4 solution had a sulfuric and ammonia smell.
Should I use another solvent like turpentine?
But aside of that, it looks like the decarboxylation works really well!

Pumukli - 17-4-2018 at 10:32

In Scr0t's pirrolidine synthesis there is a lot of turpentine, a small ammount of spearmint oil and no DMSO - although the reaction time is 20 hours at reflux temp. (around 160 C) and he had had solubility problems. He suggested using a small ammount of DMSO to help with the solubility though.

Link:
http://www.sciencemadness.org/talk/viewthread.php?tid=64791

So yes, turpentine may help.

On the other hand I can't really help with the side reaction, the reddish color of phosphoric acid soln. or the mini explosion. Btw. wasn't this later one caused by a simple mechanical blockade of the vapour path in the condenser? Was not this blockade caused by (methyl)ammonium-carbonate build-up?

Edit: added the link

[Edited on 17-4-2018 by Pumukli]

DIBALL - 17-4-2018 at 13:50

Quote: Originally posted by Pumukli

In Scr0t's pirrolidine synthesis there is a lot of turpentine, a small ammount of spearmint oil and no DMSO - although the reaction time is 20 hours at reflux temp. (around 160 C) and he had had solubility problems. He suggested using a small ammount of DMSO to help with the solubility though.

[Edited on 17-4-2018 by Pumukli]

I think I try to do it, like he did. Don´t think the DMSO will help with the solubility, since it dissolved gylcine really badly. But the reaction worked perfectly fine without it dissolving. Also I think that this reaction will proceed a lot faster.

Quote: Originally posted by Pumukli

On the other hand I can't really help with the side reaction, the reddish color of phosphoric acid soln. or the mini explosion. Btw. wasn't this later one caused by a simple mechanical blockade of the vapour path in the condenser? Was not this blockade caused by (methyl)ammonium-carbonate build-up?

[Edited on 17-4-2018 by Pumukli]

The vapor which condensed, build up these crystals over time, so that they blocked the whole reflux condenser and the gas couldn´t escape anymore. Than the stopper flew out of the flask with a small bang. How do you assume, that it was (methyl)ammonium-carbonate?

I have put this reddish liquid in the freezer for one hour and it was syrupy. Normal water in this amount would´ve be frozen in 10 minutes.
I let it in the freezer now and then try to filter.

But has anyone an idea, if there was (or could be) a reaction between the DMSO and glycine? Didn´t had advanced synthesis chemistry in Uni...

UC235 - 17-4-2018 at 19:43

Quote: Originally posted by zed

I've seen those videos. Copper Carbonate works poorly. Copper Chromite works very well. Seems to me Doug's Lab has a nice procedure.

I mentioned this because Nicotinic Acid, seems structurally quite similar to the imino-acids we are attempting to decarboxylate.

Copper Chromite accomplishes this decarboxylation, at right about 100 C.. A much lower temperature than that employed in most procedures.

Copper Chromite is specific for aromatic COOH groups in the presence of pyridine-like ligands. The traditional option is refluxing quinoline and copper powder. I don't believe it will work on glycine.

Doug's Lab procedure is mine from Prepub, tacked onto Magpie's pyridine thread, which is itself a modification of Ordenblitz's procedure.

zed - 18-4-2018 at 13:36

I'm suggesting that Copper Chromite might be effective for decarboxylating Amino-acid Imines.

[Edited on 18-4-2018 by zed]

Melgar - 19-4-2018 at 15:42

I mentioned using DMSO + spearmint as a catalyst once, but eventually realized that DMSO was an oxidizer under high-temperature conditions. Try using propylene glycol, if that's what you're trying to do. Maybe methylsulfonylmethane? Or even naphthalene? Or cetyl alcohol? The solvent barely seemed to matter if there was spearmint oil present.

zed - 19-4-2018 at 15:55

Napthalene might be a good idea.

In these days of difficult and expensive, solvent purchase, I can buy Napthalene for about 4$ per pint-pound.

Hadn't thought of it, and I like it.

Stinky though.

In the past, I have considered the use of Camphor.

DIBALL - 22-4-2018 at 12:57

Quote: Originally posted by Melgar

I mentioned using DMSO + spearmint as a catalyst once, but eventually realized that DMSO was an oxidizer under high-temperature conditions. Try using propylene glycol, if that's what you're trying to do. Maybe methylsulfonylmethane? Or even naphthalene? Or cetyl alcohol? The solvent barely seemed to matter if there was spearmint oil present.

Right, I thought that something like that might be a problem...
I already tried PG, but someone said, that this could react too.
I will do it the classic way with turpentine. This shouldn´t be a problem?
Also I think, that methylamine is quite soluble in some things like DMSO and a lot of it stayed in solution. I´ll try it the next days with turpentine and HCl solution. The mystery solution that I got from the phosphoric acid reaction, was no surprise, just phosphoric acid...

Naphthalene is a bit too much paperwork, where I live...

zed - 25-4-2018 at 14:00

Naphthalene purchase requires "paperwork" where you live?

Here in Oregon, last month, I saw it both at The Dollar Tree and Walmart.

About $4/pound, OTC..

Tell me more, tell me more.

DIBALL - 30-4-2018 at 17:38

Good news everyone!
I had 2 productive days and a lot new and interesting was witnessed!

So I tried it with turpentine and was disappointed, that it was a lot slower than DMSO! 50mL of it and 5g glycine with 8 drops of spearmint and after an hour only about 30% reacted.
But I realized, that it already started to bubble (a tiny bit) before even heating! Also I thought, that it reacted better at a lower temperature, since only a few bubbles came over when boiling, instead a lot when I started heating, but it was probably due to the heating air.

This let me think, that I should try it in water. So same setup and 50mL of water, which almost dissolved everything.
Almost no bubbles came, when it was boiling, so I stopped after 1h. Then I added, after it was just warm, some NaOH solution and it started to bubble (keep that in mind). But it just made me mad and didn´t notice, what it actually meant.

Then I got pissed (not the Australian kind) and thought "screw this!" and added 200mg of basic copper carbonate, water, peppermint and glycine.
After one hour no change...
I left it over night to cool and the next day I was surprised, that half of the flask was full of white solid. Since the glycine dissolved almost entirely and the copper carbonate was blue and only 200mg, I thought, that some reaction has happened. Then I realized, that zed said, that it might be methylamine carbonate! It also clogged my condenser and aside glycine it couldn´t be anything else! If it was ammonium carbonate, the bubbles should have been more vigorous during this reaction (which didn´t happen this time), due to the methane formation!

I thought, that it should be a positive, if I add some NaOH and it bubbles. So I did!
Some drops (I already stepped away, because of my high expectations) and nothing happened... added till pH10... nothing.
Then I added till pH 14 and still no gas (but the insoluble solid disappeared!). I hooked it to the bubbler and no bubbles...
Then I smelled it and it smelled like ammonia and bit fishy!!

I was finally happy, that all reactions since the first spearmint try were a success! While I was cleaning the flask I realized, that I could´ve heated it, but it was already gone.

I restarted with 40mL DMSO, 8 drops of spearmint, 4g of glycine and a 20mL 5% HCl solution. Since I wanted to treat myself for this discovery, I celebrated this, by adding a stir bar for the first time during this research.
I set it to stirring and brought it to reflux. A lot of bubbles arrived during the refluxing and it kept up, almost constantly, until only 20% of the glycine was left (after 30-40min). I stopped heating, because the condenser was about to get clogged once again...

It was brilliant to watch the glycine bubbling, even though it was under 100C! The reaction just wants to happen! I cooled it in an ice bath and on the flask sides a lot of crystals appeared! A strong ammonia sent was noted after opening the flask.
I added NaOH solution and the sent got stronger! I reattached it to the bubbler and a few bubbles appeared then! After reheating, the bubbler received more bubbles than usual.

I changed to distillation and decanted the glycine that didn´t react. I heated the solution and since I didn´t want any decomposition, I applied a weak vacuum (260 mmHg). at around 80C vapor came over, but started to solidify on the condenser. I stopped the water circulation and the problem didn´t appeared anymore. The temperature rose soon and I turned the vacuum off, to see the "real temp". It was 110C and the steam dissolved the solid. I stopped the vacuum, after the temp rose again for a bit. And was left with 14mL of a two layered solution, where the upper one, had particles floating around. With a bit of smelling, I assumed, that it was probably peppermint and a bit of DSMO with out desired substance.
The heated flask was cloudy with fine sized particles (not like glycine!).

I´m thinking about filtering this one and the other one is in the freezer. After one hour at -20C it is still a liquid.

Conclusion:
Everything works as we expected! The failures actually have lead to the insight, what was actually going one and how much is actually possible!
The decarboxylation appeared as predicted, but mostly the methylamine didn´t gas out, instead got stuck in the solution as methylamine carbonate...
With NaOH it is possible to gas it out, but due to the great solubility of the methylamine, it stayed in the solutions. The best way to separate it, is distillation or crystallizing it, which isn´t really an option in DMSO due to the high melting point. With the copper carbonate method it should be possible, if you get rid of the copper or react it with NaOH and boil it, till most of the gas is out of solution.

So the methods, that should be possible:

1. Peppermint, solvent (preferably DMSO) glycine, reflux → bubble in HCl and then distill the solution of the initial beaker → react with NaOH and bubble in the HCl solution → evaporate → purify?

2. Water, basic copper carbonate, glycine → let it react under reflux → cool it down, so a lot precipitates → filter → get rid of copper carbonate → purity?

3. Since the first tryings of our research worked, but not qualitative (or the supposed ammonium chloride was just the methylamine carbonate). I suggest, that the NaOH solution is added slowly drop wise and not whole!
I think, that the excess of NaOH lead to the demethylation of the amine! But just a guess...

Okay, since I didn´t have done a qualitative test of the products yet, we shouldn´t be too euphoric (or maybe it´s just me

). But I couldn´t find any reason, why it should´t work. The next days I will do the final steps and try to find the purity of it.

So what do you guess? Any additions? You noticed something, that I did not? Also it would be great, if some people around here, could recreate my processes and verify (or not) our findings!

Quote: Originally posted by zed

Naphthalene purchase requires "paperwork" where you live?
Tell me more, tell me more.

In a country, that needs paperwork for methanol, because some stupid drunks used to drink it or sold it as spirit, cause they were too cheap and too dumb to distill!

[Edited on 1-5-2018 by DIBALL]