Pages:
1
2
3 |
tr41414
Hazard to Self
![*](images/xpblue/star.gif)
Posts: 56
Registered: 14-9-2006
Location: EU
Member Is Offline
Mood: No Mood
|
|
I'm actually a bit late... but...
The reaction is well documented on orgsyn...
www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv7p0099
Can you use MonoSodiumGlutamate as a precursor? just one CO2 to be striped of before our final compound... The same reaction should apply for GABA,
just adjusting the weight (molar ratio)... I am wondering if that CO2 would get of if someone accidentaly ingested some of the compound (anyone know
of psychological activity GBL-g-carboxylic acid)?
There's also a more sophisticated method for producing substituted GBL's, but it is not very economic unless you will produce some ultraGBL analogs
(dunno if anything like that exists).
www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv7p0400
Method uses too much of hard to get / watched chemicals, but could be made almost OTC (read notes), you are also limited by volaitility of the olefin
used. Someone should try the rxn with styrene (the compound produced should be as useful as plain GBL ) and make a report (i don't have GAA needed and i just found out that my beautiful liquid styrene turned into chunk of
solid PS ).
|
|
jimmyboy
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 235
Registered: 1-3-2004
Location: Texas
Member Is Offline
Mood: No Mood
|
|
just oxidize THF -- far easier to come by
|
|
ExothermicReaction
Harmless
Posts: 22
Registered: 1-10-2007
Member Is Offline
Mood: No Mood
|
|
So has anyone successfully pulled off a steam distillation? How did it go?
|
|
Nicodem
Super Moderator
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Steam distillation or what? Of GBL? It does not steam distill. Please UTFSE before posting! There is a thread exactly on this issue already.
|
|
Eclectic
National Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 899
Registered: 14-11-2004
Member Is Offline
Mood: Obsessive
|
|
Nicodem, please UTFSE before telling people to UTFSE! A search for "steam gbl" returns no hits. And this thread says that GBL steam distills
1g/10ml. I don't know that I believe it, but I think that's what the post is saying.
GBL Steam Distillation Thread
OK, azeotropic distillation, not steam distillation.
Maybe we should be telling people DON'T UTFSE! Use Google site:sciencemadness.org (search terms). ![:(](./images/smilies/sad.gif)
[Edited on 10-2-2007 by Eclectic]
|
|
Nicodem
Super Moderator
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Yet you found it nevertheless. It is all matter of technique.
|
|
Eclectic
National Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 899
Registered: 14-11-2004
Member Is Offline
Mood: Obsessive
|
|
Yea, well I've been doing computer searches for over 30 years. I mean for the sake of the newbies.
|
|
ExothermicReaction
Harmless
Posts: 22
Registered: 1-10-2007
Member Is Offline
Mood: No Mood
|
|
Thanks Eclectic. I can see that its not so simple.
Nicodem : The reason I didn't do an intensive search for the topic is that I was replying to Organikum's comment in this thread where he says :
"I always thought that GBL is best steamdistilled. At 100°C and ph 5-5,5 the equlibrium GBL/GHB is to 80% on the GBL side - the removal of GBL by the
steam should push the equilibrium further into the right direction.
IIRC the Ullmann names this procedure as one way to produce GBL.
This should make the workup easy and solvents obsolete."
The only response to his posting was "Thank you. Dealing with all that DCM was not so attractive."
Can you see why I might have inquired further in this thread?
Nice to meet you both. I'm new here, and am not an expert in this field, but its important to me that I gain the respect of the locals. I hope to
contribute as I gain knowledge.
|
|
maxidastier
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 118
Registered: 3-4-2010
Member Is Offline
Mood: No Mood
|
|
Poor yields and not easier
|
|
jon
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 459
Registered: 11-1-2006
Member Is Offline
Mood: paranoid distrustful apprehensive
|
|
not to mention thf + oxidizers= bad idea
go to wikipedia and look at the enthalapy of combustion it's off the charts like 3800 kj/mol
it would appear that steam distillation would make this process much easier the main concern is nitrosamines as artifacts of the diazotation.
i think ghb is good if it is used responsibly but in the hands of the "rave scene" it can be disasterous.
what's going on is with that HNO2 it's unstable at room temperature and it disproportionates.
i forget exactly the equation it's a little early i'll get back to it.
but the noX produced forms nitrosamines.
my memory is a little vague but is'nt it true that strong acids decompose NOx compounds?
if i had'nt indulged myself in truckload quantities of mdxx compounds i suspect i would be a little sharper than i am now.
[Edited on 11-7-2010 by jon]
[Edited on 11-7-2010 by jon]
|
|
roamingnome
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 363
Registered: 9-9-2006
Member Is Offline
Mood: No Mood
|
|
my digital merck at least archives monograph 4840
Monograph Number: 4840
Title: g-Hydroxybutyrate
CAS Registry Number: 591-81-1
CAS Name: 4-Hydroxybutanoic acid
Additional Names: g-hydroxybutyric acid; 4-hydroxybutyrate; gamma-hydroxybutyrate; GHB
Molecular Formula: C4H8O3
Molecular Weight: 104.10.
Percent Composition: C 46.15%, H 7.75%, O 46.11%
Line Formula: HOCH2CH2CH2COOH
Literature References: Endogenous constituent of mammalian brain; thought to function as a neurotransmitter or neuromodulator. Biosynthesized from
g-aminobutyric acid, q.v.; freely crosses the blood-brain barrier. Prepn of salts: A. Saytzeff, Ann. 171, 258 (1874); C. S. Marvel, E. R. Birkhimer,
J. Am. Chem. Soc. 51, 260 (1929). Acute toxicity: B. Bruguerolle et al., Thérapie 32, 375 (1977). GC-MS determn in biological fluids: S. D.
Ferrara et al., J. Pharm. Biomed. Anal. 11, 483 (1993). Clinical pharmacokinetics: idem et al., Brit. J. Clin. Pharmacol. 34, 231 (1992). Clinical
studies in narcolepsy: L. Scrima et al., Sleep 13, 479 (1990); in opiate withdrawal: L. Gallimberti et al., Neuropsychopharmacology 9, 77 (1993).
Review of efficacy in alcoholism: G. Biggio et al., Adv. Biochem. Psychopharmacol. 47, 281-288 (1992). Review of potential role as neurotransmittor:
G. Tunnicliff, Gen. Pharmacol. 23, 1027-1034 (1992); of neuropharmacology and abuse potential: R. Bernasconi et al., Trends Pharmacol. Sci. 20,
135-141 (1999).
Derivative Type: Sodium salt
CAS Registry Number: 502-85-2
Additional Names: g-OH; sodium oxybate; sodium g-oxybutyrate
Manufacturers' Codes: Wy-3478; NSC-84223
Trademarks: Somsanit (Köhler); Gamma-OH (Clintec Nutrition); Xyrem (Orphan Med.)
Molecular Formula: C4H8NaO3
Molecular Weight: 127.09.
Percent Composition: C 37.80%, H 6.34%, Na 18.09%, O 37.77%
Properties: Crystals from alcohol. LD50 in male, female rats (mg/kg): 2,000, 1,650 i.p. (Bruguerolle).
Toxicity data: LD50 in male, female rats (mg/kg): 2,000, 1,650 i.p. (Bruguerolle)
but offers scant information of solubility data
see, having read the few threads on the sandmeyer reaction, which is really neat how nitrous acid works on a primary amine
but the debate lingers as to the DCM ,salting out, vacuum or not to vacuum , in other words the workup
so to the post reaction mother liquor I merely added a molar equivalent of KOH in minimum extra water. The color changed slightly to a deeper less
greenish yellow. I refluxed this for a bit and started the slow march of distillation. As I went to add vacuum to continue progress some mother
liquor belched up into the receiving flask. Serendipitously I evaporated this as a little check of whats going on. I can post a picture but it is a
white crust
now i assume this to be a mixed cation Na and K of chloride and butyrate. I now am thinking of ways of further confirming the products of the
reaction. Is there some solvent out there that will effect the butyrate and leave the chlorides.
Other then patience this workup is like a breeze so for along.
|
|
digitalemu
Harmless
Posts: 38
Registered: 21-10-2010
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Misanthropy ![](images/xpblue/lastpost.gif) | Any updates to this? Pure GABA can be sourced very cheaply from China by now. Sodium Nitrate is available and cheap as well from your one stop
internet auction site. Al-Chymist has cheap DCM & Chloroform.
Come on, let's see some results! What of this distilling issue? Problematic?
[Edited on 31-7-2006 by Misanthropy]
[Edited on 31-7-2006 by Misanthropy] |
NaNO2 is NOT Sodium Nitrate(NaNO3), it is SODIUM NITRITE(NaNO2). Mixing up the two could lead to bad things as Nitrite is quite a bit more toxic
than Nitrate. Careful out there and make sure you know EXACTLY what you are working with.
|
|
shulgin
Harmless
Posts: 1
Registered: 5-12-2012
Member Is Offline
Mood: ecstatic
|
|
hello,
There is one thing I am curious about that rhodium synth that maybe someone could explain to me. after you have added your hcl to the NaNO2/GABA
solution, the synth seems to tell you to hit that with NaHCO3 and then pull with the dcm?
That's how I read the synth, but in my mind it does not make sense, it makes most sense to pull the gbl with dcm after the HCl reaction, and then
distill off the dcm and hit the gbl with the NaHCO3.
Of course in his workup he refers to three seemingly different remaining distillates, so i'm not really sure of the end procecedure he's trying to
convey.
Thanks for your time!
<3 xoxo <3
|
|
Jesse Pinkman
Harmless
Posts: 13
Registered: 28-8-2012
Member Is Offline
Mood: No Mood
|
|
Hi shulgin,
you should first react the GABA/NaNO2 mix with a mineral acid to form the HNO2 and then the diazonium salt, which then converts to GHB.
As I have read from the attached paper, the GHB slowly loses H2O to form the lactone - in this case GBL. This in my opinion why one should wait
"usually 24-36 hours" according to the recipe.
Quote: |
The rate of this reaction, however, is relatively slow in mildly acidic solutions, and significant conversion of GHB into GBL requires a time scale of
several hours (or longer) for solutions of pH 2.0 or greater.
|
The reverse reaction (hydrolysis of the lactone) is rapid and exothermic.
And finally - I have read in MSDS-s for DCM, chloroform and ethyl ether, that one must work with them always in a fume hood, because of their vapors,
which can cause loss of consciousness.
As the attached paper states : "Consequently, ethyl acetate was selected as the most appropriate extraction solvent to recover GHB as a pure residue."
Hope that this answers your question ![:)](./images/smilies/smile.gif)
Attachment: Extraction_GHB_Aqueous_Solution.pdf (150kB) This file has been downloaded 3386 times
|
|
bmays
Hazard to Self
![*](images/xpblue/star.gif)
Posts: 55
Registered: 30-9-2012
Member Is Offline
Mood: No Mood
|
|
Just distill it, atmospheric is fine but all glass is necessary. Discard the first bit, shut it off when the residue starts to burn. Makes a mess of
the flask but easier and cheaper then dealing with massive quantities of solvent.
|
|
Aaron.j.hard
Harmless
Posts: 2
Registered: 16-4-2011
Location: Australia
Member Is Offline
Mood: Indecisive
|
|
Hi All,
Second Post Please be Kind !!
I was wondering if one could extract GHB / GBL from the reaction distillate by means of a Bisulfite adduct.
Will The GHB / GBL Carbonyl Group enable a SMBS Adduct Like a Ketone ?
1#
Prepare a saturated solution in Water of Sodium Sulfite / Sodium Meta Bisulfite and extract the crude Reaction distillate.
2#
Wash the crude reaction distillate with DCM and then Extract the DCM With a saturated solution in Water of Sodium Sulfite / Sodium Meta Bisulfite.
Filter the adduct and free the product By addition of a base solution such as Sodium Bicarbonate or , Sodium Hydroxide, the Bisulfite is liberated as
Sulfur Dioxide.
Just a thought , Thanks.
|
|
Hockeydemon
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 218
Registered: 25-2-2013
Member Is Offline
Mood: No Mood
|
|
Can someone please inform me if I'm misunderstanding the attachment Jesse Pinkman left?
After performing the sandmeyer reaction with GABA, NaNO2, & HCL, and allowing the rxn to rest for 24+hrs. The best way to extract to extract the
GHB would be to saturate the post rxn mixture with NaCl, and to add acid until there is a pH below 3 which would convert the vast majority of the GBL
to GHB? Then add ethyl acetate, and then distill out the GHB. Then bring the pH back up to 7 with NaOH. Then pass the the GHB/ethyl acetate/H2O
through a column of MgSO4 in order to remove any H2O. Then finally allow the ethyl acetate to evaporate.
Or am I just way out of my league here? haha
[Edited on 10-7-2013 by Hockeydemon]
|
|
Hockeydemon
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 218
Registered: 25-2-2013
Member Is Offline
Mood: No Mood
|
|
Post sandmeyer rxn GBL/GHB extraction questions
I have a few questions about this reaction, and the product's extraction. Also I could use some clarification on the attached .pdf file. Please note I
have already read every thread I could find using a site specific Google search on this topic.
After the rxn is complete most methods recommend you allow the solution to sit for a minimum of 24hrs. Is this so newly formed GHB cyclizes to it's
lactone form? Is there any reason that this is preferable when it comes to extraction?
While distilling ~500mL of post rxn solution at atmospheric pressure ~300mL of crystal clear liquid distills over at 98C.
Everything that I read seems to imply that you cannot distill this over at atmospheric pressure, and you must distill under vacuum because of the high
boiling point/azeotrope of GHB/GBL. Yet the distillate that is formed at atmospheric pressure when boiled down to remove the water turns into a wax
block. What is this then?
------
Now on to the .pdf attached.
It says that a rxn solution with a pH less than 3 in a saturated solution of NaCl provides the best environment for GHB extraction because the GBL is
converted to the free acid form. It also says that ethyl acetate is the most preferable solvent for extraction (yet everyone uses DCM. Why?).
So in theory couldn't you run your sandmeyer rxn, and then saturate the solution with NaCl & make the pH<3. Then simply extract it with some
ethyl acetate in a sep funnel? Then bring the pH back up to 7 allowing the lactone to form again. Then you could dry the solution with MgSO4, filter
the salt, and evaporate the ethyl acetate? Why would this not work?
------
I get the impression that I'm missing some fundamental concepts in my thought process otherwise I would have been able to simply look this information
up & find this. Sorry if this should be in the beginnings section.
Attachment: Extraction_GHB_Aqueous_Solution.pdf (150kB) This file has been downloaded 936 times
|
|
Nicodem
|
Threads Merged 11-7-2013 at 07:54 |
Nicodem
Super Moderator
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Hockeydemon ![](images/xpblue/lastpost.gif) | After the rxn is complete most methods recommend you allow the solution to sit for a minimum of 24hrs. Is this so newly formed GHB cyclizes to it's
lactone form? |
I think the kinetics of this equilibrium are pretty fast, especially under catalyzed conditions (which low pH assures). The 24 h are certainly not for
this reason. But why don't you ask the author of the procedure? Whichever procedure that is? You don't refer to any.
Quote: | Is there any reason that this is preferable when it comes to extraction? |
Whether the 4-hydroxybutyric acid or its lactone form is preferable for the extraction depends on their corresponding logP. Calculate them for octanol
and compare. But in any case, in aqueous solution they are in equilibrium, so you can't have only one or the other, there are always both present.
Quote: | Everything that I read seems to imply that you cannot distill this over at atmospheric pressure, and you must distill under vacuum because of the high
boiling point/azeotrope of GHB/GBL. Yet the distillate that is formed at atmospheric pressure when boiled down to remove the water turns into a wax
block. What is this then? |
I don't know. You formed it, you analyze it.
It's not like you gave us any experimental to do guesswork on. I'm not one of those members that believe hypotheses can be built on non-existing data.
Quote: | It also says that ethyl acetate is the most preferable solvent for extraction (yet everyone uses DCM. Why?). |
Perhaps they don't know the logP of the product in CH2Cl2? Or perhaps they have no ethyl acetate or n-butanol? Perhaps
they have a surplus of CH2Cl2. Perhaps they don't care for the contamination with halogenated solvents. There are plenty of
possible reasons.
Quote: | So in theory couldn't you run your sandmeyer rxn, and then saturate the solution with NaCl & make the pH<3. Then simply extract it with some
ethyl acetate in a sep funnel? Then bring the pH back up to 7 allowing the lactone to form again. Then you could dry the solution with MgSO4, filter
the salt, and evaporate the ethyl acetate? Why would this not work? |
Why would it? Surprisingly enough, many compounds just don't jump out pure out of mixtures, regardless of how strong your wishful thinking is. Just
how do you think butyrolactone can be isolated from such a mixture in any effective way without applying fractional distillation? Did you hear about
the laws governing the partial pressures of components above their liquid phase mixture? Well, I guess that part of the theory eludes you. Another
thing that eludes you, is the irrationality of your belief that the other components, like the crap and the non-volatile side products, would just
disappear by itself, without applying a distillation.
Quote: | I get the impression that I'm missing some fundamental concepts in my thought process otherwise I would have been able to simply look this information
up & find this. |
Yes, you do miss certain fundamental concepts. The problem with fundamental concepts is in that they are fundamental, meaning that you would better
learn them before venturing any further into their application. Being ignorant of fundamental concepts is all just fine, as long as you don't
try to apply that ignorance in possibly life threatening situations. For example, personally, I'm totally ignorant of nearly all the fundamental
concepts that are inhumanly possible in such a wast universe. For this reason, when it comes to experimental work, I rather limit myself into the
application of only those concepts that I'm familiar with, or learn the new ones first and apply them later. If none of this is possible, I design
experiments with great caution.
…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!
|
|
Hockeydemon
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 218
Registered: 25-2-2013
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Nicodem ![](images/xpblue/lastpost.gif) |
I think the kinetics of this equilibrium are pretty fast, especially under catalyzed conditions (which low pH assures). The 24 h are certainly not for
this reason. But why don't you ask the author of the procedure? Whichever procedure that is? You don't refer to any.
|
You're right I should have provided reference. On this Rhodium write up it says 'once the reaction is done proceed to extract (usually 24-36hrs later).' The .pdf attachment says that the free
acid form of GHB is unstable, and will readily revert back to it's lactone form after awhile. If the kinetics of the reaction are fast - especially
under catalyzed conditions wouldn't the GHB be converting to it's lactone form by waiting?
Quote: |
Whether the 4-hydroxybutyric acid or its lactone form is preferable for the extraction depends on their corresponding logP. Calculate them for octanol
and compare. But in any case, in aqueous solution they are in equilibrium, so you can't have only one or the other, there are always both present.
|
Thank you. While we've learned about partition coefficients in school I was always provided with the values to do the math. I was unaware that it was
such a simple thing for me to perform. I will have to do this on a few things.
Quote: |
I don't know. You formed it, you analyze it.
It's not like you gave us any experimental to do guesswork on. I'm not one of those members that believe hypotheses can be built on non-existing data.
|
You're right - I just figured doing so would be frowned upon. I have questions about the synthesis, but I did not want to appear to just be asking you
how to make it.
Quote: |
Why would it? Surprisingly enough, many compounds just don't jump out pure out of mixtures, regardless of how strong your wishful thinking is. Just
how do you think butyrolactone can be isolated from such a mixture in any effective way without applying fractional distillation? Did you hear about
the laws governing the partial pressures of components above their liquid phase mixture? Well, I guess that part of the theory eludes you. Another
thing that eludes you, is the irrationality of your belief that the other components, like the crap and the non-volatile side products, would just
disappear by itself, without applying a distillation.
|
You're right again - that was undoubtedly a really dumb question that I already knew the answer to.
Quote: |
Yes, you do miss certain fundamental concepts. The problem with fundamental concepts is in that they are fundamental, meaning that you would better
learn them before venturing any further into their application. Being ignorant of fundamental concepts is all just fine, as long as you don't
try to apply that ignorance in possibly life threatening situations. For example, personally, I'm totally ignorant of nearly all the fundamental
concepts that are inhumanly possible in such a wast universe. For this reason, when it comes to experimental work, I rather limit myself into the
application of only those concepts that I'm familiar with, or learn the new ones first and apply them later. If none of this is possible, I design
experiments with great caution. |
I never had nor have any intention of consuming, or letting anyone consume anything that comes from my experimenting. I'm too cautious/paranoid to try
it myself, and too responsible/ethical to risk doing harm to others. I'm acutely aware of my lack of knowledge.
I do appreciate the response to my questions. I'm sure I'll have more after I do some more reading. Thank you.
|
|
Hockeydemon
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 218
Registered: 25-2-2013
Member Is Offline
Mood: No Mood
|
|
GHB & GBL via sandmeyer rxn problems?
I was reading about a person's synthesis online and I can't figure out what is going wrong in their synthesis.
Quote: |
The person placed 1 mol of GABA (103g), 69g of NaNO2 (food grade), and 230ml DH2O to a 1L round bottom flask. They then added 115ml HCL (technical
grade) dropwise with a rate of ~1 drop/8 seconds with heavy stirring. Once the HCL was fully added stirring continued for ~1hr, and was then
transferred to another flask. This procedure was then repeated in order to obtain ~900ml of rxn mixture. The solution was allowed to sit overnight
with light stirring to allow the rxn to come to completion (room temperature was ~0 Celsius due to weather). After ~20hr the rxn mixture was placed in
a room temperature environment. After the 24hr period the rxn mixture was placed into a 1L rb flask again, and was set up for simple distillation.
The distillate collected was ~400ml of crystal clear liquid. It had a pH of ~6-7, and no noticeable odor. The distillate was brought up to a pH of
~7-8 using NaOH (food grade). This fluid was then transferred to a beaker and boiled down to 100ml and allowed to cool. No solidification occurred so
it was further boiled down to 50ml, and cooled. No solidification - the liquid now had a slight yellow hue to it, and a slightly salty taste, and ever
so slightly more viscous.
The post rxn mixture was placed in the freezer to precipitate any NaCl, and then decanted off. It was then placed back into a simple distillation
until bumping occurred. Then placed back into the freezer to encourage more NaCl precipitation. Once decanted for the final time ~350ml of post rxn
fluid was placed into a 500ml sep funnel and washed with EtOAc in 200ml portions 5x times.
The EtOAc was placed into a 1L rb flask with a fractional distillation column. Once all of the EtOAc was collected from distillation ~25ml of dark
brown liquid remained. The 25ml was then placed into a micro distillation setup and distilled under vacuum ~5ml of crystal clear liquid was recovered
with a pH of ~5.
The discard fluid from the EtOAc washes was now comprised of over 50% salt, and the remaining liquid was a few shades off black.
|
What exactly is going on in this procedure that would result in no GHB, and very little GBL? I can't find anything wrong with it, and have looked over
the erowid procedure to no avail.
Here is the rxn mechanism.
![](http://www.drugs-forum.com/chemistry/chemistry/pictures/gaba2ghb.gif)
|
|
Nicodem
|
Threads Merged 8-12-2013 at 02:13 |
Nicodem
Super Moderator
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
Provide references when citing! Edit your post correspondingly.
|
|
Hockeydemon
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 218
Registered: 25-2-2013
Member Is Offline
Mood: No Mood
|
|
I am unable to because the forum that it is off of is something you have to be granted access to. That is all of the information though.. Nvm though
someone else worked it out. The guy mistakenly bought L-glutamine rather than gaba powder.
[Edited on 8-12-2013 by Hockeydemon]
|
|
Hockeydemon
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 218
Registered: 25-2-2013
Member Is Offline
Mood: No Mood
|
|
While trying to help that guy on the other forum someone mentioned that Jazz pharmaceuticals is attempting to make an extended release version of
Xyrem using deuterium.
This had me wondering about replacing the HCL in the sandmeyer rxn synthesis with DCL. It has the same chemical properties as hydrogen -just heavier.
DCL is relatively inexpensive from Sigma-Aldrich, but of course that is not much of an option for most of us. However there is a publication online
describing a relatively easy synthesis of DCL.
C6H5OCl + D2O --> C6H5COOD + DCL
C6H5OCl + C6H5COOD --> (C6H5CO)2O + DCL
A Convenient Procedure for the Preparation of Deuterium Chloride
J. Am. Chem. Soc., 1942, 64 (9), pp 2223–2224
DOI: 10.1021/ja01261a054
Publication Date: September 1942
Would there be anything wrong with doing something like this? I read that deuterium pharmaceuticals take ~50% longer to metabolize.
![](http://www.drugs-forum.com/photopost/data/500/600px-GHB_metabolic_pathway.jpg)
The metabolic pathway using alcohol dehydrogenase would deprotonate the deuterium atom that the sandmeyer rxn left. Wouldn't this all make it
relatively simple to make extended release GHB?
I also thought that the the deuterium would exchange protons with the surrounding water in the reaction so you could maybe do the whole rxn in D2O? It
appears that placing deuterium on a metabolically labile position is preferable according to this .pdf
Quote: |
Substitution of hydrogen(s) at a metabolically labile position with deuterium is a strategy employed to attenuate metabolism Deuteration should have a
negligible effect on the biological activity and physical chemical properties of a compound, as deuterium is a naturally-occurring, stable,
non-radioactive isotope of hydrogen [12]
A deuterium-carbon bond is more difficult to break than a hydrogen-carbon bond, thus deuteration of a
labile position should slow metabolite formation involving hydrogen-carbon bond scission
[13]
|
Thoughts anyone?
|
|
Zyklon-A
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1547
Registered: 26-11-2013
Member Is Offline
Mood: Fluorine radical
|
|
I been waiting to try this reaction. I got all the reagents and have done the first half.
I added 15.4 grams of GABA (.15 mols) with 10.4 grams of NaNO3 (.15 mols). This was dissolved in 34.8 mL of water. I then added
.16-.17 mols of HCl (aq) drop-wise over a period of three hours.
So now I have a clear solution of GHB with sodium ions, chloride ions and probably a bunch of other stuff. (I don't know exactly what all the reaction
products are.) My question is: Do I have to distill it? There isn't much solution there, and yields won't be great if I do. I
plan on using chloroform as a solvent - which isn't miscible with water. So would the GHB just go into the bottom chloroform layer or will
other crap dissolve too?
GHB appears to be very soluble in chloroform, and sodium chloride is insoluble.
[Edited on 15-5-2014 by Zyklonb]
|
|
Pages:
1
2
3 |