Author Topic: Yet another OTC GBL extraction  (Read 5783 times)

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raybeez

  • Guest
Yet another OTC GBL extraction
« on: August 07, 2004, 10:50:00 PM »
Apologies to everyone who is sick of seeing posts re: this topic, but Swim has found a product with high potential for lactone extraction, and has some actual chemistry related questions on the procedure.

Swim has found a product with an MSDS listing the following:

Gamma butyrolacetone <60% (w/w)  96-48-0
Orange Sweet <1% (w/w) 8028-48-6
C9/C11 Fattyalcoholethoxylate <1% (w/w) 68439-46-3
Benzylalcohol >5% (w/w) 100-51-6

Swim is guessing the remainder of the product would be H2O?

Questions:
1) How to get out the benzyl alcohol.. it has an almost identical BP as the lactone, so distillation wouldn't be possible right? Is there a solvent extraction that could be done, or could the product be steam distilled out following a typical NaOH rxn with the lactone?

2) Swim is worried about the identity of the ethoxylated alcohols.. a search for the CAS # in chemfinder.com gave no info on its identity except a BP of 180 C. Would this be a mixture of compounds? Its less than 1% w/w, but SWIM is still worried about health risks and such.. any advise for the removal of this(these) compounds?

Thanks for all the help.

methyl_ethyl

  • Guest
Ethoxylated Alcohols
« Reply #1 on: August 08, 2004, 02:50:00 AM »
The ethoxylated alcohols are added for surfactant properties.  The C as you probably would have guessed represents Carbon the numbers 9-11 representing the chain length.  Yes these products are the result of reactions between several alcohols of varied chain lengths and Polyethene Oxides of varied chain lengths as well.  I would assume that there is not a well defined boiling point, as each carbon chain would more than likely have a different boiling point (I am guessing). 

Because these alcohols have a lipophilic alcohol end and a hydrophilic ethoxy end, and I assume each chain length has different hydrophobic and hydrophilic properties I see it creating a "phase" between a polar and nonpolar.  This may or may not be able to help you in your situation.  If you really wanted to get rid of this you would probably have to sacrifice yield and totally remove the surfactant phase.  You would probably have to find the correct temperature where the surfactant is the least soluble in the phase that you want to keep, or perhaps the range that this substance boils will be acceptable for distillation. 

As far as toxicity goes, it seems that most nonionic surfactants pose little threat in there purest form, "the low toxicity associated with these substances is markedly increased with the inclusion of various caustic substances such as sodium tripolyphosphate and various carbonates and other corrosive substances in the 'low-phosphate' group." (Poisindex)

From Poisindex (Micromedex) for CAS 68439-46-3

 0.5 RANGE OF TOXICITY

    * A) Ingestion of nonionic or anionic detergents alone is not generally serious.

regards,

methyl_ethyl


raybeez

  • Guest
One question down...
« Reply #2 on: August 08, 2004, 06:47:00 PM »
methyl_ethyl, thank you for your well informed reply.. SWIM will have to weigh out his options for addressing the ethoxyalcohols but will keep in mind that they only make up 1% of the product (w/w)...

As for the Benzyl alcohol, swim knows that normal distillation would be impossible as both BA and GBL have bp's of 204C (per Merck index).

Could the GBL be steamed distilled out or would the BA come over as well? Is there a solvent extraction that could be done to remove the BA? SWIM could also just react the product with a strong base, crank up the temp to 140-150, hope all bad stuff steam distills out leaving relatively pure GHB in solution.

Any thoughts?

amine

  • Guest
Salt it out....
« Reply #3 on: August 10, 2004, 01:56:00 AM »
why not react the gbl with a base (NaOH), then distill the benz. alcohol under vacuum, you should be left with crude NaGHB which you can convert back to gbl which you could distill to achieve greater purity.

yei

  • Guest
Perhaps a gentle oxidizer would convert that...
« Reply #4 on: August 10, 2004, 05:49:00 AM »
Perhaps a gentle oxidizer would convert that annoying benzyl alcohol to benzoic acid, which could be carefully neutralized to make it stay as a salt in a water phase.

Something like, say, hydrogen peroxide and a pinch of copper sulfate or KMnO4?

I would try to keep the stuff, though. So useful...

Perhaps refluxing the mixture with NaHCO3 to make GHB-mixture, followed by repeated washings with things like acetone(?) or petroleum ether which GHB may not be soluble in. This should remove the benzyl alcohol, which will be miscible with them, as well as the surfactants.


raybeez

  • Guest
Seems doable..
« Reply #5 on: August 11, 2004, 12:28:00 AM »
Converting the lactone to NaGHB followed by vacuum distillation is doable..same with solvent extractions..

Would a bicarb reflux be the best way to go, or NaOH? Swim doesnt want side rxns going on with ethoxyalcohols and Benzyl alcohol present...

swim dreams about reacting the lactone, boiling off the 33% H2O in the product, heat the mixture up to 130-140 to boil off excess lactone, then remove heat source and immediately attach distillation apparatus.. as temp falls, but before NaGHB hardens with the BA in it, apply vacuum and hopefully distill off the BA? Or maybe it would be better to leave a bit of H2O in the mix ...

For solvent extracts, swim has lots of pure ethyl acetate, and can possible get pure acetone or PetEt but he isnt sure.. swim would prefer solvent washes to pull BA into an organic solvent leaving gbl/ghb in an aqueous layer, but isnt going to bother hunting down solvents unless he knows for sure it would work.

Swim thanks everyone for their advice and help.

yei

  • Guest
Do some research
« Reply #6 on: August 11, 2004, 05:44:00 AM »
since it seems that you intend to do semi-large scale production, it might be worth your time to take 20 ml samples of the mixture and test various solvents on them.

Actually, why doesn't someone here at the hive report the partition coefficients of GHB salts in various solvents? That would be a great source of knowledge to the hive. All it would require is pure GHB powder and some time. Of course all the GHB could be recovered at the end, so just some time and will, for the good of all...


Rhodium

  • Guest
All GHB salts are *very* polar
« Reply #7 on: August 11, 2004, 03:52:00 PM »
why doesn't someone here at the hive report the partition coefficients of GHB salts in various solvents?

No need to - any GHB salt will be so polar that >99.5% of all dissolved material will be present in the aqueous phase, regardless of what solvent the other phase consists of. If you choose methanol as the polar phase, >95% of any dissolved GHB salt (quantitatively, significantly less than in a comparable volume of water) will stay in that layer.


yei

  • Guest
Then
« Reply #8 on: August 11, 2004, 05:31:00 PM »
Conversion to GHB followed by ethyl acetate washes to remove the benzyl alcohol, perhaps followed by recrystalization would seem to be an efficient way...


Rhodium

  • Guest
(Fatty) Alcohol Ethoxylates
« Reply #9 on: August 11, 2004, 08:38:00 PM »
Distillation would probably not be a bad idea either. The alcohol ethoxylates are (not too healthy) surfactants, and cannot be washed away easily as they are soluble in both polar and non-polar solvents:


Alcohol ethoxylates (AEOs)

(http://scholar.lib.vt.edu/theses/available/etd-05112004-170001/unrestricted/Brian2.pdf)

Alcohol ethoxylates (AEOs), alcohol propoxylates (APOs), and alkylphenol ethoxylates (APEOs) are non-ionic surfactants. The term surfactant covers surface active compounds characterized by their ability to concentrate at surfaces and to form micelles in solution. AEOs, APOs and APEOs contain two main molecular regions:

(1) the oligoether region, a hydrophilic chain, and
(2) the alkyl region which is hydrophobic (Fig 1).

CH3(CH2)xCH2O-(CH2CH2-O)yH

Figure 1.
x = No. of methylene unit repeats in the alcohol (10-16 is common).
y = No. of ethylene glycol ether [ethoxylate] subunits in the polyether chain.


APEOs are similar in structure to alcohol polyethers, they contain a benzene ring situated between the two regions found in alcohol polyethers. Since the mid-1940s APEOs have been used commercially for their surfactant ability. They have been used in a wide variety of applications including: industrial process aids, dispensing agents in paper and pulp production, emulsifying agents in latex paints and pesticide formulations, flotation agents, industrial cleaners (metal surfaces, textile processing, and food industry) and household cleaners. Certain APEOs have been determined to be estrogenic in fish, birds, and mammals. Due to the potentially toxic effects of some APEOs and their degradation products, alternative surfactants have been used in their place. Alcohol polyethers have been used in place of APEOs for residential and industrial uses.

Fatty alcohols, used in the formation of alcohol polyethers, are obtained from natural and synthetic sources. Coconut oil and tallow are the most commercially attractive sources of fatty alcohols because alcohols produced from their triglycerides are in the effective detergent range (C12-C18). Fatty alcohols obtained from natural sources are almost exclusively linear and contain only even number carbon alkyl chains. Synthetic alcohols can contain either an even or odd number of carbon atoms and can be either 100% linear or 20-25% branched, depending on the method of their formation. Production of alcohol polyethers is performed by reaction of ethylene oxide or propylene oxide with fatty alcohols. Acidic or basic catalysts can be used for polyether formation. A mixture of adducts result from competition between the epoxide and the initiator (fatty alcohol) and formed adducts. The synthesis of these compounds can result in a complex oligomeric mixture of fatty ethers that contain a distribution of either EOs or POs of varying chain length.







raybeez

  • Guest
Good to know..
« Reply #10 on: August 12, 2004, 12:17:00 AM »
Good to know about the NaGHB solubility... swim is thinking that he'll do the following:
(recall product is 60% gbl, 33% H2O, 5% benzyl alcohol, 1% ethoxyalcohols, 1% orange scent stuff)

1) Distill off most of the H2O.. some GBL will likely steam distill over, hopefully along with some of the other crap, which will probably all be discarded (since

2)Distill under vacuum below the reduced BPsof gbl/benzyl alcohol to hopefully remove most of of the ethoxyalcohols

3) React gbl/benzyl alcohol with NaOH(aq) until pH 7, praying that it doesn't hydrolyze any remaining ethoxyalcohols to evil things

4) Extract benzyl alcohol with ethyl acetate (probably a single wash would be fine?)

5) Concentrate aqueous extract down into NaGHB(s).

What does everyone think? Swim would rather NaOH be used for hydrolysis simply due to abundance of pure reagent available to him, but if risky would be okay using bicarb.

raybeez

  • Guest
Frustration
« Reply #11 on: August 21, 2004, 07:48:00 AM »
Swim is one frustrated bee.. has just spent the last 8 hours trying to purify this product with no luck. Swim is praying someone out there can offer further suggestions/assistance with this.

Recall the MSDS for swim's product lists the following:
GBL <60%
Benzyl Alcohol >5%
C9/C11 fatty ethoxy alcohols <1%
Orange Sweet <1%

Swim is assuming H2O makes up the remainder

Here is what Swim tried:

1) Steam distill out the water. Heated product gradually up to 140 degC and no boiling occurs, just a steam rises from the liquid that smells very acrid and orange like (product is 1% orange sweet). Following heating, liquid takes on an orange/yellow colour (clear with a yellow tint before).

2) Swim tries to vacuum distill at 12 torr.. hits 70 degC.. 80 degC... liquid has bubbles in it, but they aren't breaking the surface at all, and nothing is distilling over.. temp increased to 90 degC (GBL has a bp of 89 at 12 torr) and mixture starts bubbling but still nothing comes over. Finally, at 100 degC, a few drops come over.. swim checks them and they taste soapy and citrusy with no hint of GBL. Distillate is miscible with H2O.

3) Swim begins to wonder if there is H2O in product. What else could it be, since 30% of the ingredients arent listed on the MSDS? Swim adds some H2O to the original product, and bam, too layers form. Top layer is H2O layer, bottom layer is ?? with micelle bubbles sitting at the interface between layers.

4) Swim takes some of the product, heats it to 100 degC and adds NaOH in H2O. Exothermic reaction occurs, and two layers form. Top (aqeuous layer) is removed, and reacted with more NaOH until pH = 7. Micelle bubbles are still present in this layer, and is still giving off citrus smell.. perhaps the orange sweet?. Swim begins to steam distill, as temp hits 125 degC product reacts further and white precipitate is formed. Precip. is vacuum filtered out, and has a soapy texture and a sodium initial taste followed by a soapy after taste. Precip is insoluble in cold/hot h2o and ethyl acetate.

Swim doesnt know what else to try.. he let the remainder of the liquid cool, and it didnt turn into NaGHB.. just sat there and gave off acrid citrus odor.

Swim was sure that any GHB would be in the top (Aq layer) per Rhodiums previous post. Swim is going to go smoke some kif but would really welcome any further suggestions of things to try.

Peace.

raybeez

  • Guest
Tried again with better results
« Reply #12 on: August 23, 2004, 06:24:00 AM »
Tried it again with better results.. did the following:

1) Heated 100mL of otc product with GBL to 110 degC

2) Dissolved 0.68 mol NaOH in H2O (1g/2.5mL), (assuming 60mL of the 100mL of product was GBL) and slowly added it into product while mag stirring

3) 2 layers formed during the addition of the NaOH(aq). Tests showed that the _bottom_ layer was actually the aqueous layer! Bottom layer had an orange colour.

4) When 80% of the NaOH (aq) was added, ph of the bottom layer was taken, and found to be 12

5) 15mL more of otc product was added to the mixture while stirring at 110degC. pH of the bottom layer was found to be ~7.

6) Solution was cooled, and bottom aqueous layer was removed via sep. funnel

7) Aqueous layer (still orange) was boiled until H2O was removed.. temp hit 125degC and product immediately started solidifying



8) Poured into pyrex dish to harden.. looks like NaGHB! Product cooled, slightly wetter than Swim is used too, somewhat strange consistancy, slightly brown in colour, smells okay, taste is initially fine but has a strange aftertaste. Bioassay +ve for GHB (whoop!) but product seems slightly weaker then normal.



So: Swim thinks there's still some kind of impurity in the G.. it's brown and taste is definately off. Also, it solidifies instantly at around 125degC. Normally, swim can heat it up to around 150degC, maintain the temp until h2o is all bubbled away, then the GHB cools as the temp drops.

Swim tried the following cleanup:

1) Re-dissolve GHB in H2O and wash with ethyl acetate, then boil off water and re-solidify it.. ethyl acetate seems to have pulled _nothing_ out of the discoloured GHB, and no improvement in product is noted

2) NaGHB is dissolved in H2O (0.5g/mL) and is steam distilled to hopefully remove impurities. Distillate has slight aroma of orange sweet but tastes exactly like pure H2O. No improvement in product is noted.

What else can swim try to purify?? Even if no one decides to help, Swim wants to thank everyone for their input so far, as product definately seems consumable.

Peace.

n00dle

  • Guest
Seems like it's never going to come out clean...
« Reply #13 on: August 26, 2004, 05:17:00 PM »
Seems like it's never going to come out clean unless that surfectant is removed. Since it's a stubborn one, and i assume its not a biodegradable surfectant, is there anything we can put in there to force the degredation of that surfectant? Or since ghb salts are very polar, what about converting it to the salt and then washing the ghb with lots of nonpolar in a buchner funnel or something to pull the surfectant out?

Someone just touted using silica particles + n-hexadecyltrichlorosilane + toluene as solvent to make something to remove the surfectant. Not sure if this can be directly applied here, but maybe this can provide food for thought.

icexool

  • Guest
evaporation
« Reply #14 on: September 19, 2004, 04:46:00 PM »
Can't you just take your GHB solution, and start evaporating the water and then dump it on a cold metal plate? So the powder will preticipate...
I've also read in the GHB compilation that if you make Na-GHB salt that you will get a solution of 50% GHB in 750ml water and if you evaporate to 50% of it's volume that Na-GHB will preticipate in the liquid, will that work insted of the alcohol procedure...

raybeez

  • Guest
Not exactly sure what your talking about here..
« Reply #15 on: September 20, 2004, 04:18:00 AM »
Not exactly sure what your talking about here..

The problem is that SWIM has impure NaGHB.. Swim has no trouble getting NaGHB from his OTC product, it just has a strange aftertaste, is off-white in colour, and is maleable instead of being rock hard firm after SWIM boils off the H2O from the NaOH(aq) he is reacting with the OTC product.

Swim is pretty sure the impurity is a decomposition product of the surfactants and NaOH instead of benzyl alcohol.. rational for this theory is as follows:
- Swim adds dH2O to OTC product, and two layers form; top layer is the H2O layer and is clear
- Swim heats product up to 110°C and adds dH2O and two layers form; top layer is the H2O layer and is clear
- Swim heats product up to 110°C and adds NaOH(aq) and two layers form; top layer is NON-Aqueous, bottom layer is now aqueous layer and takes on a yellow-orange tinge that persists all the way through to the final NaGHB

Whatever it is, non-polar washes don't get rid of it.. haven't tried to distill it out again once swim has a NaGHB(aq) + Impurity(aq) mix since he figured it was just BA present.. will try again when he has time.



Can't you just take your GHB solution, and start evaporating the water and then dump it on a cold metal plate? So the powder will preticipate...




icexool

  • Guest
I know he does, I just didn't know in what...
« Reply #16 on: September 20, 2004, 01:06:00 PM »
I know he does, I just didn't know in what topic to post this question, so I thought this was the most relevant one...
Can you just evaporate the water off...?

raybeez

  • Guest
Evaporating NaGHB
« Reply #17 on: September 21, 2004, 09:22:00 PM »
Yes, you can take an aqeueous solution of NaGHB and evaporate off the water by heating it to around 140°C and holding the temperature there until the solution stops bubbling.. then pouring the liquid into say a pyrex baking dish and quickly saran wrapping it so that it's airtight. As the solution cools, it will solidy into NaGHB(s).

Any searching on the hive or examination of files on rhodium.ws and you would have found this.

icexool

  • Guest
I did find it I just wanted to confirm this.
« Reply #18 on: September 22, 2004, 11:29:00 PM »
I did find it I just wanted to confirm this.
Just like with some synths on rhodium say you need to boil the GBL with NaOH or heat the GBL to 100*c and then add NaOH some say solid some say aquaous solution.
And some say it may not boil but be around 60-80*C.
I just don't know anymore what to do/believe.

indole_amine

  • Guest
GHB: an emerging recreational drug
« Reply #19 on: October 08, 2004, 05:30:00 AM »
Gamma-hydroxybutyric acid: an emerging recreational drug
(P. C. A. Kam & F. F. Y. Yoong)
Anaesthesia Vol. 53 Issue 12 p. 1195 (December 1998)
DOI:

10.1046/j.1365-2044.1998.00603.x






Abstract
Gamma-hydroxybutyric acid (GHB) is no longer used as an anaesthetic induction agent because of the high incidence of myoclonic seizures and vomiting. However, it is used occasionally in Europe for the treatment of narcolepsy, alcohol dependence and opiate dependence. Since the early 1990s, GHB has become a drug of abuse in youths for its euphoric, sedative and anabolic effects. Common adverse effects include a rapid onset of drowsiness, nausea, vomiting, myoclonic seizures and coma of short duration. Clinicians should be alert for these adverse effects and consider the possibility of GHB abuse in young adults with unusual clinical presentations in the emergency department.




indole_amine