Author Topic: For the vindication of Eleusis - Methylamine  (Read 23210 times)

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Organikum

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What smokemouth wrote and Rhodium wrote this...
« Reply #180 on: August 25, 2004, 09:16:00 AM »
What smokemouth wrote and Rhodium wrote this also in his FAQ, is of course right. Hexamine, paraformaldehyde - no alcohol present, the reaction proceeds through a pathway where serious amounts of formaldehyde are transformed into CO2 and lost for the reaction. Therefor the formaldehyde is the limiting reagent here, adding some (para)formaldehydewill give better yields but this and the temperatures (109°C) will form more di-methylamine.

Reactions with (ethyl)alcohol added form, so done right no CO2 as stated in the patent and proven by experiment. The loss on formaldehyde is then limited by the amount of alcohol present. The addition of ammoniumchloride presents an good excess of this and suppresses together with the lower temperatures the formation of di-methylamine almost completely.

There is no contradiction, we talk about two different reactions, the reaction of commercial formaldehyde containing alcohol represents probably a mixture of them. Ethylalcohol is preferable over methylalcohol.

I hope this clears things up.
ORG

PS: I am not going further into wild speculations on what exactly happens. I merely presented a patent which was referenced in one of the leading journals of or. chemistry, I had good success in reproducing procedure and claims of the patent and others too. I posted a picture where it can be seen how methylamine looks like freshly recrystalled from IPA. Most pictures I had seen looked somehow like a lot of ammoniumchloride to me.  :(  
I will do some work on the workup soon - it seems to be not trivial for many here and indeed the extraction of methylamine.HCl from a lot of ammoniumchloride is not trivial - time, heat and stirring etc., but thats no problem of this synthesis I presented. If one has problems to get the workup going as described by me, use the one from Vogel´s or from Org-Synth.
There are several methods on howto do the synth and the workup available - dont blame others if you have problems but try another way which may suit you better.


armageddon

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practical info
« Reply #181 on: August 26, 2004, 02:15:00 AM »
Of course I could be wrong; but it could very well be that the following is true, when seen in comparison with my observations, no?

When using the following ratios, the IG-Farben reaction was a clear solution at the beginning; upon heating, a white fluffy precipitate appeared (NH4Cl) and disappeared when the rxn temperature surpassed 47°C. This IMO means that the amount of water is at the minimum of what is possible to get the reaction still going - enough to dissolve everything in the beginning, but as soon as any EtCOOH is formed, the solution gets not only milky but the solubility of NH4Cl suddenly gets reduced, because EtOH (low solubility of NH4Cl) is replaced by EtCOOH (NH4Cl insoluble) and therefore the overall solubility of NH4Cl in the reaction is lowered - and as soon as the temp. is high enough to cause partial evaporation of EtCOOH (accompanied by rxn becoming clear again), the solubility of NH4Cl rises again (white precipitate disappears again).


Now here are the ratios:


200g hexamine
24.5g NH4Cl
200ml H20
220ml EtOH
675ml HCl 31.45% (and a pinch to compensate for evap losses during addition)

(As said, I think that this nears the absolute minimum amount H20 that can be used sucessfully, maybe even less works too - but remember Placebo who got bad yields without any water...)


Now here's another variation, adapted to fit abacus'/placebos complains about molar ratios being detrimental  ;) :

Chill everything, mix in said order, place in oil bath, set up for distillation and gradually apply heat over 3h *slowly*, until 75-80°C rxn temp. are reached and formate starts to come over (with steam temp no higher than 50°C!), then heat to 95°C *very* slowly over the course of the next three hours while watching for those small bubbles starting directly below surface instead of big ones arising from the flask bottom/stirbar (leuckart-like!) and collect almost pure EtCOOH which, upon washing with dilute brine and drying, amounts to ~165ml; meaning a NH4Cl/HCHO ratio of 1 to 1.53 after esterification - calculate it for yourself...  :)
- oh, and in case I had used more additional NH4Cl like Organikum did originally, the molar ratio after partial esterification, i.e. the ratio of formaldehyde:NH4Cl reacting would be 1.42:1 - isn't this exactly the same ratio like in Vogel's?

So if it is true that ethanol mainly serves the purpose of accelerating the reaction (thus enabling for less formaldehyde being necessary - without alc, the rxn is driven by excess HCHO), then the purpose behind adding NH4Cl would be to bring the molar ratio of "products used up in the reaction" to the same as in Vogel's...(again you can recalculate that yourself if u want)

(SHIT! I broke a long thermometer again!! This time 250°C/30cm measuring depth  >:(  :(  >:(  - seems like methylamine via EtOH-leuckart does hurt my thermometer collection very bad...)

Greetz A


armageddon

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*real* brain food
« Reply #182 on: August 27, 2004, 07:57:00 AM »
OK I think I made a mistake when doing the calculations for my above post... sorry!

Here's the correction to it:

200g hexamine = 1.42 mol => 4 * 1.42 mol NH4Cl + 6 * 1.42 mol HCHO
24.5g NH4Cl = 0.46 mol => total amount of NH4Cl is 5.68 + 0.46 = 6.12 mol

 this means 6.12 mol NH4Cl and 8.52 mol HCHO.
 now I got ~165ml C2H5OOCH from this; meaning 2.04 mol.
 So I can be sure that when EtCOOH is collected, 2.04 mol HCHO will have reacted.
 Now let's calculate the amount of HCHO being still available:

8.52 - 2.04 => 6.48 mol HCHO

And now the ratio between NH4Cl and HCHO after esterification:

6.48 mol / 6.12 mol = 1.06 => ratio is roughly 1:1, slight excess HCHO - but maybe there were losses during purifying the EtOOCH; then the ratio would be exactly 1:1...

Now for comparison reasons the ratio before esterification:

8.52 / 6.12 = 1.39 => ratio roughly 1.4:1, excess aldehyde - but of course the excess gets smaller when more NH4Cl is added; and numerous posts show that yields are quite good when doing so...




Now as you can see, the alcohol brings an excess of HCHO (how big excess depends on the amount of additonal NH4Cl) down to an equimolar amount compared to NH4Cl, while allowing for a slow temperature rise over a long time, in contrast to the standard method, involving brute heating to 105° from beginning on.

In other words: alcohol accelerates the reaction by pushing the equilibrium towards products - no big excess HCHO necessary to get things going! (at least not 50% excess like with the old hex method, but rather 1 : 1.4 like with the Org.Syn. method, which uses methanolic formaline.. Or even smaller excess, if more NH4Cl is used - just watch out for solubility problems  :) )
Alcohol further could avoid overalkylation through binding any free formic acid by esterification (at least the nitrous acid test for sec amines was negative for me), and, lemme rephrase: this reaction is a leuckart reductive methylation! (not my idea but some PhD's!) ..and with leuckart rxns, better results are obtained with slowly rising the temperature over a long time, not by heating with full power for x hours!

Think about it.


Greetz, A


Organikum

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If it makes you and some PhDs happy than the...
« Reply #183 on: August 27, 2004, 11:41:00 AM »
If it makes you and some PhDs happy than the reaction is a Leuckard. Or wet socks or nosedriller or whatever you like. It doesnt really matter, same as solubility of the NH4Cl doesnt matter as this is stated in the patent and was posted by me before: Not all NH4Cl goes into solution at once but dissolves whilst heating up/during the reaction. The importance of heating up SLOWLY was also emphasized by me already.

This thread is running in circles now, whatta nonsense and confusion.

And now dont come and say it does matter as because the right conditions were already presented without any mystic reactionpathway innards readings it doesnt. Period. You dont have to be a hen to know how to make a tasty omelette.

Ever heard about: "The urge to express oneself lengthy and self-opinionated under the influence" ? Yes? Read part two: "The strong wish not having oneself expressed lengthy and self-opinionated AFTER the influence is over".

Not to piss you off armer-geddon  ;)  I share my most private experiences here with you...  ;D .

COOL DOWN!

ORG


armageddon

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OK, no more experimental data then
« Reply #184 on: August 27, 2004, 05:25:00 PM »
You dont have to be a hen to know how to make a tasty omelette.

:)  - obviously some bees would like to be a chicken though; I just thought I could supply them with info on how to become one...  ;D


Not all NH4Cl goes into solution at once but dissolves whilst heating up/during the reaction

And sometimes, it goes completely into solution at once, but partly precipitates upon applying heat...


But you're right; the outlines for a successfull procedure were given long before in this thread - I just wanted to throw into discussion a few new thoughts about ratios, molarities etc. to provide thought food to those trying to find a mechanism that explains why alcohol is helpful (some bees are not content with knowing that it works nice but also want to know why it does - or maybe better said they want to know why they don't get good results?)

I could still think of *several* ways of varying the rxn parameters to learn more about possible mechanisms and stuff; but as you said, the outlines for a successful application of the patent were given, and it is up to everyone to make his own guesses about why it works the way it does.

Just thought I could help in doing so by providing more data (its always better to start from experimental data rather than from speculations when trying to find out about rxn mechanisms  :) ) - but as you think it isn't necessary...



Not to piss you off armer-geddon  I share my most private experiences here with you... .

COOL DOWN!


Probably you're right with that as well  :)  - well supervising a rxn for >12h isn't that exciting; so I tried to get some diversion by bragging about how it could possibly work - I still think my theory has some right points in it...




About the workup - I advise to use the following procedure:

after concentrating the remainder (orange syrup) to dryness and letting it cool/solidify, add small amount of IPA, crush up solid cake and decant IPA (save it). This contains methylamine HCl and most of the orange impurities.
Now add some 300ml IPA (for 200g hexamine used in the beginning) and reflux it for 30 minutes, then decant the IPA into other beaker and let slowly let cool to -7°C, filter precipitated MeAm crystals, rinse them with acetone, chloroform and again acetone, let dry for a short time and place in sealable container. The washes will form a 2-layer system in filtering flask - clear upper layer acetone and red bottom layer CHCl3.
Now place the mother liquor (without the washes!) into your flask with MeAm/NH4Cl-cake again, and reflux again for 30 minutes, then repeat the decanting/cooling/filtering/washing and add the so obtained crystals to the first crop. Repeat this 4-5x with same mother liquor, then extract one last time with small amount of fresh IPA.

Combine the small first, dirty extract with the remaining mother liquor and final IPA rinse and concentrate under vacuum, then cool, filter and rinse with tone/ChCl3. Recrystallize from ~250ml boiling IPA per 50g of raw product to get clear, colorless crystals of good purity.

The good thing is that you only have to deal with dirt and byproducts (by thoroughly washing/crushing up inside funnel) when crystallizing the contents of the first small extraction; the following xtractions (using same mother liquor) will contain substantially less impurities and result in clean crystallization of the product - but will account for the major amount of isolated MeAm...

A


armageddon

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again couldn't resist...
« Reply #185 on: August 28, 2004, 09:28:00 PM »
To those considering it being of interest - old thread, same topic:


"I know that the following reactions occur to produce the methylamine:

Hexamine + 4HCl __> 4NH4Cl + 6CH2O

CH2O + NH4Cl __> CH2NH + H2O + HCl

CH2NH + CH2O + HCl __> CH3NH3Cl + HCO2H

Now I know that CO2 is produced from the formic acid, but how?  Something must be reduced in order to oxidize the formic acid to CO2.  What is being reduced?  Another molecule of formic acid to formaldehyde?  The imine?

It seems that the sum of the last two reactions is overall reversible.  Therefore, formic acid must be removed to drive it to completion.  The most probable mechanism is that two molecules of formic acid react to form formaldehyde and carbonic acid.  This reaction is probably also reversible.  In order to drive the synthesis to completion, the carbonic acid must be removed by dehydration to CO2.  This would mean that the lower the pressure that the reaction runs under, the faster it will proceed.  This also means that theoretically, 1 mole of hexamine contains exactly the right composition to produce 4 mol of methylamine and 2 mol of CO2, with no excess of any reactant.


(

Post 374164 (missing)

(lab_bitch: "Stoichiometry of Methylamine Synth from Hexamine", Chemistry Discourse)







To those having access to libraries:

E. A. Werner, Methylation by Means of Formaldehyde. Part I., J. Chem. Soc., pp844-853 (1917)

H. I. Jones, The Preparation of Methylamine, J. Am. Chem. Soc.(?), pp1411-1515 (1918)







..and even the esterification concept isn't new - but its advantages wheren't realized back then, as the common practice was/is to push the reaction equilibrium to the right side through CO2 removal, rather than formic removal:

"The reason that your reference does not mention CO2 evolution probably arises from the fact that the procedure uses formalin, which contains ~10% methanol and removes the formic acid via its methyl ester before it can decompose."

(

Post 374511 (missing)

(terbium: "No gas is evolved.", Chemistry Discourse)



;D

A


LaBTop

  • Guest
Stop whining.
« Reply #186 on: September 13, 2004, 04:56:00 PM »
1. Nobody owes any thread or post in all these forums, every member decides by his own free will to come here and to contribute. So who are you to say this thread is dead?
(Anyone of you out there perhaps think this is YOUR playground, but we think it's OUR playground, which means all of us, and we are not the easy intimidated kind of people.
We particularly don't like to be rapped over the knuckles about the way we moderate. So thread carefully around here. :o )
Btw, I just saw that the members can't see WHO rates them.  :) . You would like to know, but I won't tell,  ;) . Ask around if curious.

2. The subject of this thread has been beaten all over the bushes, it's time to make room for some eventual additional practical input.
About the simple addition of an alcohol to a just as simple reaction.
Which has been discussed ad infinitum by now.

3. I assure you all that the more experienced members here are the ones who have been ROTFL, reading all this nitpicking about some theoretical wanking, after the first good posts.

Just imagine you are a nervous, underground chemist or cook ( a big part of this board is meant for them!), who needs the least possible attention from his surrounding neighbours, let alone the law.
Ofcourse that person will choose the Abolt or BondDoubleBond beaker way, but will do it in f.ex. a bottle in a warm water or oil bath, so the smelly byproducts can be lead through a hose to 2 washbotles in line, in a box outside a window even; the first one bigger and empty, the last one smaller and filled 3/4 with tap water. That way you can eat your breakfast beside the ongoing reaction, and won't smell a thing. (see btw my red remarks in the Biffman post)
No suspicious glassware, nothing out of the ordinary.

And a professional would ofcourse do it his/her way, and not bother at all to ask you backyard rocket scientists how to do things, but use TFSE, books, the WWW and his/her logic. LT/


armageddon

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sick and tired
« Reply #187 on: September 13, 2004, 05:43:00 PM »
I surely don't want to know who gives out those unrealistic and offensive ratings out of personal dislike.

Nor do I whine.

I just see that some bees are allowed to openly throw with dirt in this thread, while others (although nobody gives 'em a scientifically acceptable explanation on why) are flamed for their efforts and aren't allowed to post defensive statements although not offending anyone.

I further don't see what practical experience could be added anymore, everything important was said in the first few posts as LT said. (>220 posts, about one "simple rxn with simple EtOH addition")

And I want to remark that the "BondDoubleBond beaker way" doesn't exist. This shit is solely abolts idea. And beakers are not the type of vessel if you want to stay undetected. They are open vessels. And your neighbours won't care if you own real glassware or baking dishes, they will just detect eventual smells. More likely if beakers are used.


Left to say:

Big "FUCK YOU" to the moderators, I'm off.....

Greetz from your "backyard rocket scientist" being not able of doing scientific research and only posting insignificant stuff...


abolt

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This shit is solely abolts idea.
« Reply #188 on: September 14, 2004, 08:50:00 AM »
This shit is solely abolts idea. And beakers are not the type of vessel if you want to stay undetected. They are open vessels. And your neighbours won't care if you own real glassware or baking dishes, they will just detect eventual smells. More likely if beakers are used.

Well.........the thread is titled "for the vindication of elusius", a guy who told us all years ago that Methylamine could be made easily, with simple equipment.

For those of you who are challenged with the english language, I will provide the meaning of the word "vindication":

vindication (noun) - The defense, such as evidence or argument, that serves to justify a claim or deed.

The "Methylamine in a beaker" post merely "vindicated" the earlier work of Elusius. ;)

Other comments Deleted, out of respect for LT.


LaBTop

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Abolt,
« Reply #189 on: September 14, 2004, 01:57:00 PM »
Why must you insult him this way?
To my feeling, he's trying hard to defend his particular view on the subject, but both of you slipped off to namecalling.
This is totally unnescessairy.
The argument one uses, doesn't loose any importance in the eyes of the beholders, without all the insults.

This was the last time we warned you all not to use personal insults in the chemistry forums.
Any one caught from now on, will get banned for a few days, to cool off.
And my last banning spray is years ago, so save me from that macho behavior, pretty please. LT/


Organikum

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Why "vindication" ?
« Reply #190 on: September 14, 2004, 03:27:00 PM »
I named this thread "For the vindication of Eleusis" because it was told that the addition of alcohol would be absolutely wrong. See Rhodiums page the "Methylamine FAQ" for example.

The patent and the following trials showed that this is not true, therefor the naming.
I disapprove the use of open beakers for this as the fumes are
- dangerous
- smelly
- unhealthy

This was already cleared at start of this thread in a short discussion with Terbium.

LaBTop, you will rarely find me critisizing rating in the chemistry forums and this here was and will stay an exception. If you dont like it - I cant help it. Of course I dont own this thread, nobody does, but nevertheless I felt a certain responsibility for it as I had started it and I believed it contained something useful for many here. Is this wrong? I doubt it.

I am with Terbium:
"Baseline doesnt exist"
Thats sad. What about reestablishing one?
Just a suggestion.

regards
ORG


armageddon

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-
« Reply #191 on: September 14, 2004, 06:50:00 PM »