Misanthropy
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NMP/GBL hydrolysis. Impulse goofing.
Rather than screw up the thread that spawned this: http://www.sciencemadness.org/talk/viewthread.php?tid=7538
Winding away the idle hours:
400ml of 80/20 % NMP/GBL was added promptly to a still hot, equal volume of 25% NaOH in the reflux vessel. This is placed in an warm oil bath which
was brought up to average ~130°C for 2 hours; gently boiling the supernatant. Although the bath did peak around 150°C with the last adjustment.
The vent hose was run into a water/naptha trap during this time. No activity was anticipated at the trap, however the water readily catches something,
turning milky white. No noticeable change in the naptha layer appearance or volume. Unfortunately these layers were not measured/weighed before &
after. Trap layers were seperated & dried post rxn. The water left behind a tenaciously clinging white residue. No odor of any significance this
whole time with it while evaporating. The organic layer was evap'd at room temp and a strong ketone-ish, nail polish remover-kindasorta sweetish odor
permeates the immediate area after some hours. Without ever having been up close & personal with GBL, I don't know if this odor is characteristic
of it. Oh well. It lingers here still, for no discernable reason. I'm wonding if an old can of solvents hasn't finally rusted through somewhere in
that dump of a cupboard. Maybe the wife spilled something somewhere. Crap.
The milky white, stubborn residue from the water was disposed of in short order due to company coming over & wife pissed about the damn pie plate.
Perhaps this was denatonium benzoate as the denaturant? Some trace amount is told to be in there...
I suppose solubility tests should have been checked on this. Oh well.
The reflux proceeds at a rolling boil during this time and note was made of a salty looking, heavy sediment forming on the vessel bottom. Supernatant
becomes clear, medium bown. Like Widmer Heffeweizen.  After this time period,
reflux is stopped and allowed to reach room temp.
The majority of the liquid maybe ~90% forms a top layer. Beneath this is a white, salty substance, itself atop another dense liquid layer of the same
clear, dark brown appearance, comprising perhaps another ~5% . At the bottom of all sits the first noted, salty sediment. Nothing extracted otherwise
at this point. Just placed in the freezer & allowed to seperate further. Some 4 hours of this shows a salt sediment as before, on the bottom.
Above this, to equal nearly 50% total volume, lies a blanket of delicate looking, clear crystalline mass. Perhaps Na 4-methyl amino butyrate,
primarily per this volume with possible NaGHB forming the minor sediment & saturating the solution? One supposes that cold filtration &
washing/solubility testing will follow after some sleep is achieved.
At any rate, that's where it stays for now; potential denatonium benzoate (ie Bitrex) be damned. The thought of this stuff being in there is annoying.
From here: http://www.bitrex.com/pages/technical_frameset.htm
"Depending on conditions Bitrex is generally considered to be heat stable at temperatures of up to 140°C."
What the hell manner of side product(s) might this ugly critter produce? Lidocaine? Perhaps several lighter things that may have distilled over to
some degree in any case; broken off of the denatonium at the Nitrogens? What of that benzoate?
Anyway, regarding the 4-methyl amino butyrate: It looks to me that phenibut & baclofen are possible directions. ?
[Edited on 5-2-2007 by Misanthropy]
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Nicodem
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I did not understand much of what you wrote, but I was wandering why you used an almost 4-fold excess of NaOH over GBL? Why did you heat up to 130°C?
This way you might have even hydrolyzed some NMP, though probably not much. All this makes me wander what compound is it that you want to prepare
anyway?
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
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Misanthropy
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Crude, I know, but I'm no chemist. I’m just trying to learn by observation.
I was meaning to hydrolyze both by way of excess base & heat, so long as the resultant NaGHB is not further altered in any way by this. Have I not
gone far enough? I'd like to see this NMP completely converted to 4-methylamino butyrate spoken of in Org's thread, listed above.
I was thinking of cold filtering the crystalline solids & refluxing again, this mother liquor, to see if any further conversion occurs. Might I
use even more heat?
This is my primary interest; I was merely noting the goings on at the water trap to get some feedback on it separately.
This milky white, polar distillate that dries to a small amount of white powder, makes me think in the direction of Denatonium Benzoate. It is added
in small amounts, to the original product as a bittering/denaturing compound. That's only of interest insofar as getting it out of the (hopefully)
4-MAB/GHB solution.
Both of those compounds are academically interesting in their own rights, to me. I have no practical use for either of them, nor any number of things
I wind up with. I'm doing for the sake of doing and maybe understanding the nature of these things further as I have no formal education in this
field. 
Apologies for any confusion or miscommunication on my part, and thank you for your time & consideration, everyone/anyone! 
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Misanthropy
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| Quote: | Originally posted by Nicodem
Why did you heat up to 130°C? This way you might have even hydrolyzed some NMP, though probably not much. |
Nicodem: I'm sorry for my lack of understanding here.... IIRC, You & Furch indicated that both would be hydrolyzed... Is this not so?
| Quote: | Originally posted by Nicodem
At very harsh conditions, NaOH should hydrolyze NMP to sodium 4-methylaminobutyrate. |
| Quote: | Originally posted by Furch
A little off topic perhaps, but concerning the separation of GBL and NMP, I've learned that it can be done by refluxing concentrated NaOH (20-25%),
which hydrolyzes both substances as mentioned above, and after this, the mixture is made slightly acidic. This will cause the Na-GHB to esterify
again, but not the 4-methylaminobuturate, as amides are not as easily formed as esters... Even if it's an intramolecular reaction.
Having done this, one should have a mixture of sodium 4-methylaminobuturate, GBL and water... Just distill the off the GBL.
- Furch |
So, how long & at what temp does this need to be refluxed for total NMP conversion?
Any idea if 5-hydroxy-N-methyl-2-pyrrolidone may have also resulted from my tinkering? If so, have I just complicated the situation by producing that,
along with possible 4-Methylaminobutyrate, not to mention some still unreacted NMP?
Under what conditions do these possible NMP products begin to form?
Thanks!
[Edited on 9-2-2007 by Misanthropy]
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Nicodem
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Like you quoted I said: "At very harsh conditions, NaOH should hydrolyze NMP to sodium 4-methylaminobutyrate."
I would not call 2 hours in an oil bath at 130°C with dilute NaOH as "very harsh conditions".
| Quote: | | So, how long & at what temp does this need to be refluxed for total NMP conversion? |
I don't know, but have you not considered checking the literature first?
| Quote: | Any idea if 5-hydroxy-N-methyl-2-pyrrolidone may have also resulted from my tinkering? If so, have I just complicated the situation by producing that,
along with possible 4-Methylaminobutyrate, not to mention some still unreacted NMP?
Under what conditions do these possible NMP products begin to form? |
I can't imagine how is 5-hydroxy-N-methyl-2-pyrrolidinone supposed to be a possible product. Are you suggesting an oxidation with oxygen or
what else?
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Misanthropy
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| Quote: |
I don't know, but have you not considered checking the literature first? |
Nicodem: Again, I apologize for my lack of education in this field; I'm just learning on my own (trying, anyway). I appreciate your feedback as the
breadth & depth of your insight in these things is considerable and I SWEAR I'm not trying to be rude by offering up such basic questions....
I'm not intentionally being a prick; I'm just a natural annoyance it seems.
I didn't readily find (on Google), specific documentation detailing that question. Being financially disadvantaged; I don't have an extensive
reference library & am most frequently searching the net over very poor dial up..... Might you help me locate the applicable literature?
| Quote: |
Like you quoted I said: "At very harsh conditions, NaOH should hydrolyze NMP to sodium 4-methylaminobutyrate."
I would not call 2 hours in an oil bath at 130°C with dilute NaOH as "very harsh conditions". |
Given your emphasis on that point, neither will I consider Furch's suggested concentration for simultaneous hydrolyzation, in situ, as "Very harsh",
from here on out. I was actually hoping for some greater degree of detail from one that has more knowledge than I....
From here: http://www.inchem.org/documents/cicads/cicads/cicad35.htm
| Quote: |
In air, NMP is expected to be removed by wet deposition or by photochemical reactions with hydroxyl radicals. As the substance is completely miscible
in water, it is not expected to adsorb to soil, sediments, or suspended organic matter or to bioconcentrate. NMP is not degraded by chemical
hydrolysis. Data from screening tests on the biodegradability of NMP show that the substance is rapidly biodegraded.
In rats, NMP is absorbed rapidly after inhalation, oral, and dermal administration, distributed throughout the organism, and eliminated mainly by
hydroxylation to polar compounds, which are excreted via urine. About 80% of the administered dose is excreted as NMP and NMP metabolites within 24 h.
A probably dose-dependent yellow coloration of the urine in rodents is observed. The major metabolite is 5-hydroxy-N-methyl-2-pyrrolidone.
Studies in humans show comparable results. Dermal penetration through human skin has been shown to be very rapid. NMP is rapidly biotransformed by
hydroxylation to 5-hydroxy-N-methyl-2-pyrrolidone, which is further oxidized to N-methylsuccinimide; this intermediate is further hydroxylated to
2-hydroxy-N-methylsuccinimide. These metabolites are all colourless. The excreted amounts of NMP metabolites in the urine after inhalation or oral
intake represented about 100% and 65% of the administered doses, respectively. |
Human metabolic processes wouldn't seem to be, IMO, so harsh as the reflux conditions. I don't claim to understand the biochemical implications here
and their respective degrees of 'harshness' by any means. This is why I ask if the "5-HNMP" (am I following correctly?) may have formed as well.
| Quote: |
I can't imagine how is 5-hydroxy-N-methyl-2-pyrrolidinone supposed to be a possible product. Are you suggesting an oxidation with oxygen or what else?
|
I must apologize once again. Evidently there is more to this that you, not I, seem to be understanding to a greater degree, or are intuiting something
which I am currently unable to see with such ease.
Sorry again to be such an annoyance.
[Edited on 10-2-2007 by Misanthropy]
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Misanthropy
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Wait. Is the discrepancy in my understanding here coming from a confusion between hydrolysis & hydroxylation?
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chemoleo
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And why are you posting this in a seperate thread exactly?
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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Misanthropy
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Because I'm a novice, posting in the appropriate forum. Also, I'm deviating to some fair degree, from what Org was meaning to learn from his thread in
Gen Chem.
Out of respect, I'll introduce whatever ignorance I may, into my own thread, not his.
I assume this is what you were asking?
At any rate, I took a peek at the Jug 'O' stuff & noticed 2 distinct crystalline layers, white/salty on bottom & clear/dense shards above.
Atop this crystalline cake lies a fatty, soft, off white layer. Half heartedly adhering to the solid upper crystalline layer's rough surface. Giving
& releasing with agitation.
I assume this was an unlisted thickening/emollient agent for the GBL before it was mixed with NMP; thereby forming the final product I'm tinkering
with now. Perhaps hydroxypropylcellulose or similar? The original mix was a light brown gel. Neither NMP nor GBL are said to exhibit either this
colour nor viscosity.
I don't know for sure about what it may have been, but that's my best guess. It now looks like a layer of fat from a corned beef. Or the pantry rat
soap I made as a kid. 
One compound I DON'T want appears to have eliminated itself from the mixture anyway & that's not so bad. I found the following regarding
thickening agents used with GBL. From here: http://www.patentstorm.us/patents/6156711-fulltext.html
----------------
| Quote: |
from 0.1% to 5% by weight of at least one pH stable thickening agent present in an amount effective to produce an absolute kinematic viscosity at 20°
C. of from 250-10,000 cp;
optionally, from 0% to 49% of a propylene glycol-derivative co-solvent compound having between 4 and 9 carbon atoms and between 2 and 4 oxygen atoms
per molecule, wherein said compound is selected from the group consisting of propylene glycol ethers, dipropylene glycol ethers, propylene glycol
ether esters, dipropylene glycol ether esters and combinations thereof;
optionally, from 0% to 20% by weight of a humectant/diluent which is selected from the group consisting of water, glycerol, propylene glycol,
1,3-butylene glycol and its isomers, sorbitol and combinations thereof; and
optionally, from 0% to 10% by weight of an emollient which is selected from the group consisting of fatty acid esters, mineral oil, silicone oil,
lanolin, lanolin derivatives and combinations thereof. |
------------------------
The medium brown liquid above all, about 50% total volume, is of a much thinner consistancy now. I guess I'll decant, filter & reflux with yet
more Lye. Perhaps something new & exciting will happen. Like eating the bottom out of the jug.
[Edited on 2-10-2007 by Misanthropy]
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Nicodem
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| Quote: | Originally posted by Misanthropy
Wait. Is the discrepancy in my understanding here coming from a confusion between hydrolysis & hydroxylation? |
It certainly seems so. Hydroxylation is introduction of the hydroxyl group, generally in a C-H bond but it is equally called so if the hydroxy group
replaces hydrogen on an heteroatom. As you can see if you calculate the oxidation state change, this is formally an oxidation, hence it has
absolutely nothing to do with a non-redox process like hydrolysis. Not to mention the absurdity of comparing an enzymaticaly induced transformation
with a thermally induced one under completelly different circumstances.
| Quote: | Originally posted by Misanthropy
Being financially disadvantaged; I don't have an extensive reference library & am most frequently searching the net over very poor dial up.....
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I don't know where you live but library fees are generally pretty cheap where I live, not to mention that you don't have to pay anything unless you
borrow books to take out. And given that the electronic services you need can be accessed only inside the library, you don't have to pay anything at
all. But I consider the possibility that where you live things might be different. Not all countries want their citizens to have access to knowledge,
but what is worse is that in some countries citizens fear knowledge. Therefore, I would rather see you go to the library by yourself. After all, why
should I do that?
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Misanthropy
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Thank you Nicodem, for the first post which is at least on topic.
So then, the addition of the electronegative -O in the -OH, or a resultant loss/replacement of hydrogen, is effectively an oxidation via
hydroxylation? Ok.
Now, in the case of this NMP hydrolysis, where it is opening the bond between the N and the C=O, the N gains a hydrogen whereas the now exposed
bonding point of the C=O carbon takes on an O-, rather than a hydroxyl (-OH) group per se (That's forming a carboxylic acid then, yeah?). The O &
H dissociating & bonding to seperate locations of the target molecule?
Then when acidified, maybe with H2SO4, this (dehydrates?) rips that O off that carbon (and a hydrogen from the N) causing esterification back to the
lactam perhaps? The same being true for GHB -> GBL? G-MAB -> NMP just being more difficult due to the amine being a bit more resistant to this
attack than is GHB?
Or do I still have this wrong?
| Quote: | Originally posted by Nicodem
Not to mention the absurdity of comparing an enzymaticaly induced transformation with a thermally induced one under completelly different
circumstances.
---------------
Therefore, I would rather see you go to the library by yourself. After all, why should I do that? |
Oh? Have I not seen such respectively different biochemical comparisons made by more esteemed members of this very board? Yes, I think I may have! Of
course you know quite well neither I nor anyone else is asking you to go to the library in any sense. Just hoping that you/someone more educated than
myself might freely share some very basic (respectively) knowledge.
Now kindly quit fucking with me. I'm trying here, ok? I understand that I may not take to this field so easily as most all of you may have. Why so
much shit just to obtain a little bit of insight from those who supposedly could so offhandedly give it, to the benefit of another, with so much ease
as the blink of one's eye? Am I suddenly among mewling bitches?
Even I, a nobody on this board, have gone through much greater pains (and some deal of real world personal risk) simply to help some others here with
their personal situations. Is a little directly applicable insight truly so much to hope for with regards to my idle entertainments? Not to mention
all this unrelated back & forth bullshit? I'd think not.
That being said, what do you suppose this other fatty substance may be?
Furthermore, is my idea of filtering/re refluxing the liquid with more lye at a higher temp, just folly? Are you saying Furch was wrong? What are the
specifics of these harsh conditions then? Why are those that I've imposed so inadequate? Is a rolling boil and condensation/reintroduction of
condensate, not considered a reflux? Must I introduce molten lye alone, under great pressure, somewhere near the surface temperature of the sun? Will
this be harsh enough to be considered viable reflux-hydrolysis conditions for the NMP by you?
Or may I just shove all of this right back up my ass? I guess it may as well be the next response.....
[Edited on 2-11-2007 by Misanthropy]
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Nicodem
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I don't know what all this misanthropic ranting is supposed to be for. Neither do I understand much of it since you use phrases and metaphors unknown
to my primary language. Did you found my replies offending or you just have chronic troubles with your self esteem? I'm sorry for whatever the reason
might be. But you might have considered that I'm not of Anglo-Saxon origin and have different cultural values which include the avoidance of the
hypocritical politeness. This might appear as impoliteness to you, but it is not. If you can't cope with the cultural diversity of the world, then you
can't blame me for it.
Anyway, the mechanism of amide hydrolysis can be found in any basic organic chemistry book or dedicated homepages, though there is still quite some
speculation about the step where the amine group leaves.
Once NMP is hydrolyzed it can not cyclisize back by acidification in the same fashion like GHB<->GBL. The reason is quite simple. In acid
conditions the amine group gets protonated therefore loosing its nucleophilicity (while the same is not true for the relatively nonbasic –OH
groups). You might be able to cyclisize N-Me-GABA in its zwiterionic form if you can isolate it as such and dry distill, but it can't cyclisize in
acidified solutions due to the aforementioned reason.
If your dirty NMP contains GBL and other additives then the first obvious thing to do is to distill it. You might want to use vacuum distillation
given the high boiling point (202°C). This will not remove GBL which has nearly the same boiling point, but it will remove the crap you say is
included in the commercial product. Then you might want to remove GBL by azeotropic distillation like Orgy describes and concentrate the remaining NMP
by heating it up to its b.p. (thus removing most of the water). Another way to remove GBL would be to add a slight excess of NaOH from what you expect
the amount of GBL is in there. Then you can vacuum distill off only NMP since the sodium 4-hydroxybutirate and the excess NaOH will remain in the
distillation flask (Careful not to heat too much or distill to dryness otherwise you will pyrolize it, thus contaminating your distillate of NMP. You
therefore need to use vacuum distillation in this step.).
Once you have relatively pure NMP you can go on with the hydrolysis attempt. Add, let's say, half molar equivalent of NaOH pellets and set on reflux
until most of NaOH gets consumed. You will need to check the literature on how many hours/days this requires, but I expect it will be very long (if it
the hydrolysis is feasible at all). As you see there is no other way but going to the library and consult Beilstein or SciFinder or other reference
databases. Your anti-library attitude and spoonfeeding desires can not help you with this issue, unless you have the necessary analytical equipment to
follow up the reaction.
Good luck.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Nicodem
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Misanthropy, due to a sudden attack of philanthropy, I decided to do the literature search for you. There is no reference for NMP hydrolysis with
NaOH. There are only two references for basic hydrolysis and both use barium hydroxide:
Journal of Organic Chemistry, 50(8) (1985) 1302-4.
Justus Liebigs Annalen der Chemie, 596 (1955) 158-224.
There are however several references for acidic hydrolysis:
Fudan Xuebao, Yixueban, 32 (2005) 173-177;
Latvijas PSR Zinatnu Akademijas Vestis, Kimijas Serija (1989) 472-80.
Synthesis (1981) 468-9.
Journal of the American Chemical Society, 71 (1949) 896-900.
Good luck with finding the Chinese and Latvian papers, but Synthesis was already made available and you already know where to ask for ACS
publications.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Misanthropy
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Thank you Nicodem for the assistance. I've not got any hope of finding the last 2 references but the above does, at least give me something to look
forward to.
Apologies for any...... misunderstanding on my part. Cultural or otherwise. ;-)
Peace.
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Misanthropy
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So long as I'm dorking off with a camera phone...
The juice after sitting in the sun for a week or so. Lightened up a bit.
http://img213.imageshack.us/img213/6463/thejuicesk6.jpg
The Salt layers; adhereing to them is the fatty substance.
http://img337.imageshack.us/img337/1809/saltsfattylayerstn4....
The curled, crystalline arch at one end of the solidified sediment pool.
http://img138.imageshack.us/img138/6992/crystallinearchnm1.j...
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MrG
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Does anyone know if this is doable? Everyone suggest it is but has it been done? Could I fractional freeze this out by placing in a lab freezer and
setting to -24degrees???
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