Author Topic: lactone purification  (Read 4125 times)

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armageddon

  • Guest
lactone purification
« on: July 06, 2004, 10:13:00 PM »
I once read in a patent that GBL can be purified by forming a phenylhydrazone (think it was 2,4-dinitro-phenylhydrazone..) which can then conveniently be recrystallized... (think I remember reading that something like "yellow needles" was said, but not sure about it)

- and unfortunately I am unable to relocate this useful bit of info...  ::)

But hey, can't lactones - like most ketones - be purified via the oxime (or maybe bisulf)? (just an idea)

Greetz A


Rhodium

  • Guest
How about some afterthought?
« Reply #1 on: July 06, 2004, 11:53:00 PM »
I once read in a patent that GBL can be purified by forming a phenylhydrazone (think it was 2,4-dinitro-phenylhydrazone..) which can then conveniently be recrystallized...

But as the molecular weight of butyrolactone is 86 g/mol and that of 2,4-dinitrophenylhydrazine is 198, it means that you would  need to use ~2.75 kilos of the hydrazine to purify one liter of GBL. Rather absurd if you ask me, especially considering its cost.

But hey, can't lactones - like most ketones - be purified via the oxime (or maybe bisulf)? (just an idea)

But hey, lactones are esters, not ketones...


armageddon

  • Guest
Well, I didn't think that far...
« Reply #2 on: July 07, 2004, 12:28:00 AM »
Well, I didn't think that far... (2,4-dinitrophenylhydrazine is priced at ~120 bucks / 500g (ACROS) - this way of purifying is probably more suited for preparing analytical samples than for preparative work on big scale  ;D )

But hey, gamma-butyrolactone is also called tetrahydrofuranone - so the ending "-one" doesn't stand for ketones? (funny - and the C=O in esters behaves different from carbonyl groups in ketones due to extra oxygen atom present - did I get that right?)

(sorry for my lack of afterthought)

A


Rhodium

  • Guest
Nomenclature and carbonyl surroundings
« Reply #3 on: July 07, 2004, 01:20:00 AM »
But hey, gamma-butyrolactone is also called tetrahydrofuranone - so the ending "-one" doesn't stand for ketones?

I'd say that the "-one" suffix is rather an indication of the carbonyl group "C=O" being present. By looking at it that way, all nomenclature is consistent, but you still have to evaluate the chemical structure to find out if you have a ketone (as in 2-propanone) an ester (as in tetrahydrofuranone) or an amide (as in pyrrolidinone).

(funny - and the C=O in esters behaves different from carbonyl groups in ketones due to extra oxygen atom present - did I get that right?)

Exactly. If a carbonyl group has two alkyl substituents it's a ketone, if it only has one it's an aldehyde, and if it has one alkyl group and an oxygen it is a carboxylic acid or a derivative thereof. One has to look at each functional group together with its immediate surroundings to be able to predict its behavior.


Rhodium

  • Guest
NMR Identification and Quantitation of GHB/GBL
« Reply #4 on: July 08, 2004, 07:45:00 AM »
Identification and quantitation of gamma-hydroxybutyrate (NaGHB) by nuclear magnetic resonance spectroscopy
Chew SL, Meyers JA

J Forensic Sci, Mar. 2003, Vol. 48, No. 2

(https://www.thevespiary.org/rhodium/Rhodium/pdf/forensic/ghb-gbl.nmr.analysis.pdf)

Abstract
The most common means of identification of gamma-hydroxybutyrate (NaGHB) involves using Fourier transform infrared spectroscopy (FTIR) or gas chromatography-mass spectrometry (GC-MS) of a suitable derivative. However, these methods may be complicated by possible shifts in chemical equilibrium between gamma-hydroxybutyric acid (GHB), GHB salts and the precursor lactone, gamma-butyrolactone (GBL). This paper addresses the technique of proton and carbon nuclear magnetic resonance spectroscopy (1H and 13C NMR) for the direct and accurate identification of GHB and GBL. The application of 1H NMR for GHB quantitation is also discussed.


Raver71

  • Guest
i tried gbl a bunch of times but it doesnt...
« Reply #5 on: July 31, 2004, 02:57:00 AM »
i tried gbl a bunch of times but it doesnt give you that happy mood like ghb does..its more euphoric but without the happyness...

armageddon

  • Guest
really?!
« Reply #6 on: July 31, 2004, 04:58:00 AM »
Did you know that you can convert GBL to GHB by adding 10% w/w of d.H2O to it, heating to >100°C and then adding an equimolar amount of aequous lye (NaOH, KOH etc.) dropwise?

Besides, I don't understand what you mean when making difference between euphoria and happiness - aren't you happy when u get euphoric???  :P

(I would rather say that GBL has sedative properties, whereas GHB is euphoric...)

Greetz, A


ApprenticeCook

  • Guest
ive seen this question many times.....
« Reply #7 on: July 31, 2004, 07:25:00 AM »
ive seen this question many times..... why do people eat the precursor when the drug is so easily made from it and much much better???

i dont know.... weird....
-AC


raybeez

  • Guest
Worked, but with low yields
« Reply #8 on: August 09, 2004, 05:09:00 PM »
Swim finally gave this reaction a try following chromic's writeup on rhodium.ws and had some success but seemingly low yields. Swim ran a 1mol rxn and finished with just under 70g of NaGHB(s).

Swim used ACS grade NaNO2, OTC GABA (that had been tested against a small quantity of ACS grade GABA and was found to have identical solubilities in hot/cold dH2O and EtOH) and OTC muriatic acid.

Reagents where dissolved w/ mag stirring in 300mL dH2O and chilled to below 0°C in an ice-water batch. Acid was added via an addition funnel (was worried a pressure-eq funnel would be needed, but vacuum never seemed to build up) and fumes were vented far away from SWIM using tubing.

Acid was added over the course of two hours.. went very slowly at first, keeping the buildup of yellow-brown gas under control in the rxn flask. Near the end, gas evolution diminshed, and the last 1/3rd of acid was added pretty quickly (over 15-20min). After acid addition, flask sat and stirred and bubbled at 0°C for an hour. At this point, stirring was turned off, and the rxn flask was allowed to sit overnight for 14hrs.

Upon returning, the temp was around 20°C and no bubbling was observed. Swim proceeded to setup flask for simple distillation and began steam distilling off GBL/water, but noticed as the temp increased and stirring was turned back on small gas bubbles formed in the flask (perhaps hadn't finished reacting yet?) Steam distillation continued into NaCl precip. was observed. Distillate was refluxed with ACS NaOH, boiled with 5% activated charcol, filtered, heated to 140-150degC to boil off H2O/excess lactone, and poured into pyrex dish...giving 20g or so of NaGHB. Product was hard, pure white in colour, looked identical to the product of a NaOH/99.9% GBL rxn (yay!). Had a slight tangy aftertaste however (butryic acid maybe?)

Remainder of aqueous was extracted with 5x230mL washes of ethyl acetate. Solvent was removed under vacuum, then swim was planning on distilling off the GBL, but when the temp hit around 50°C in the distillation flask, swim's vacuum failed (one of the joints in the apparatus was the wrong size, and was being held together with parafilm which seemed to melt off ruining the seal).

Distillation was continued until 92°C at 1 atm, then the 48mL of resulting yellowish/brown liquid was reacted with NaOH, boiled with activated carbon, filtered, re-heated to 140-150 °C then poured into a pyrex dish and allowed to harden into NaGHB. Yield was 48g of slightly brownish NaGHB. Swim was worried about product purity, but it tasted and smelled _fine_ (even better then the white NaGHB recovered earlier). Of course was bioassayed and +ve results (no difference in required dosing noted to 0.1 of a gram).

So... 70g yield. swim was expecting close to double that from this reaction.. what went wrong? Rxn not go to completion at the beginning? Solvent washes done incorrectly? Toss some ideas at swim as he is planning on doing the 3mol version of the run soon.

fierceness

  • Guest
It really sounds like you did everything ...
« Reply #9 on: August 10, 2004, 10:55:00 PM »
It really sounds like you did everything right, even better than when I did it.  The only thing I can see that may have caused it is that you should really not want to see ANY yellow/brown gas because seeing that gas means that there will not be enough nitric acid in solution deaminating the GABA.  If you have a problem controlling the gas, maybe you could add a slight excess of sodium nitrite and HCl.  Other than that, I can't see anything wrong!

Bwiti

  • Guest
Lets Fucking Face It..
« Reply #10 on: August 16, 2004, 03:55:00 AM »

fierceness

  • Guest
Pills
« Reply #11 on: August 17, 2004, 08:33:00 PM »
You dont want the kind in pills or even in capsules.  There exists some GABA in powdered form that you're supposed to mix in water or a protein shake or whatever.  This kind of GABA works for this synth.

18294

  • Guest
SWIM's slight modification
« Reply #12 on: August 18, 2004, 07:10:00 PM »
SWIM may attempt to make some GBL in the near future. Here is a rough outline of his plans:

Using Sandmeyer rxn to turn GABA into GBL (well hopefully, anyway)

1. SWIM will add 1 part powdered Gamma Amino Butyric Acid,  0.68 parts Sodium Nitrite, and he will also add the appropriate amount of water.

2. Next He will titrate his acid

3. He will wait 2 or 3 days for the rxn to complette.

4.He will then add dichloromethane

5. He will titrate his Base (50% NaOH)

6. SWIM will then seperate the water layer and run it through an Activated Charcoal column

7. He will acidify it until it reaches a pH of 6.5

Does anyone have any comments or anything to add to this? SWIM has done quite a bit of reading on the subject, and believes his A/B extraction of the product in combination with an AC clean would be a good substitute for the recomended distillation.

merbst

  • Guest
Re: believes his A/B extraction of the product
« Reply #13 on: August 18, 2004, 09:56:00 PM »

believes his A/B extraction of the product in combination with an AC clean would be a good substitute for the recomended distillation



As stated in this thread, there is no good substitute for the recommended distillation.  Although of course you are welcome to try! If you have success (or failure even), The Hive is happy to read what you have to say about it!  Beware of the brown gas!  Perform under a fume hood if possible, but don't put your life in the hands of your local electricity provider.


bbeeasheets

  • Guest
sodium methoxide
« Reply #14 on: August 28, 2004, 02:42:00 AM »
well after  making about 400g of GBL i took a portion aside to experiment with. One portion I added %50 NaOH (to the dcm extraction) and decanted the aqeouus. At this point I forgot to neutralize with vinegar and just boiled off the water. I took about 40g and and disloved it in boiling meoh (just enuff to disolve it all while stiring). Well the solution gradually became purple! I thought this was weird so I went back over my notes, and saw that I didn't neutralize. So I did some googling and found out that methanol and excess NaOH makes Na-methoxide... but nothing about it going purple. Is this sample salvageable? (without reconverting to gbl and distilling). I hate to toss it.

wimpy

  • Guest
I'm sorry, but isn't there any alternative to...
« Reply #15 on: September 29, 2004, 11:25:00 AM »
I'm sorry, but isn't there any alternative to sodium nitrite? Sodium Nitrite seems controlled here ... (- after searching a long time now for lots of different chemicals i have to state that the "responsible department" is doing a really good job in barring one's way ... especially annoying as GABA is so easy to obtain  >:( )
Nothing known? or even thinkable?
thanks


Rhodium

  • Guest
NaNO2 Preparation
« Reply #16 on: September 29, 2004, 08:22:00 PM »

Post 458114

(gruns: "Preparation of Sodium Nitrite: Discussion", Chemicals & Equipment)



wimpy

  • Guest
Thanks Rhodium, sounds promising!
« Reply #17 on: September 30, 2004, 12:24:00 PM »

wimpy

  • Guest
There's probably no way to separate NaNO2 from
« Reply #18 on: October 03, 2004, 11:59:00 AM »
There's probably no way to separate NaNO2 from NaCL out of a mixture of both (1-0.5% NaNO2 in NaCL)? All swim was able to find out was that both are soluble in H2O but not so good in alcohol ...


Rhodium

  • Guest
Solubility of NaNO2 & NaCl at different temps
« Reply #19 on: October 03, 2004, 01:34:00 PM »


I'd disagree. Check the tables above for a correlation of aqueous solubility of salts at different temperatures. The left shows NaCl and the one on the right shows NaNO2. As anyone can see, the solubility of NaCl does not differ much with temperature (it is always at 35-40g in 100mL water) while the solubility for NaNO2 more than doubles from 75g/100mL at 0°C to 165g/100mL at 100°C.

Thus extract the NaCl/NaNO2 mixture with boiling water (sodium nitrite being over four times more soluble than the chloride), then concentrate the extract to precipitate sodium chloride preferentially and filter hot (at room temp the solubility difference is much less).


wimpy

  • Guest
Hey! Really thanks a lot - that's kind of...
« Reply #20 on: October 04, 2004, 11:32:00 AM »
Hey! Really thanks a lot - that's kind of light at the end of the tunnel :)
But do i get this right? As far as i understand one would not be able to get pure Nitrite out of this, or ... ?
So this leads to the question: would a smaller amount of NaCL affect the reaction?
Anyway, thanks a lot, swim will try as soon as possible!


Rhodium

  • Guest
Nitrite enrichment by fractional crystallization
« Reply #21 on: October 04, 2004, 01:51:00 PM »
But do i get this right? As far as i understand one would not be able to get pure Nitrite out of this, or ...?

You have very good prospects for purifying the nitrite - for each iteration of a fractional crystallization procedure using the bare minimum of water needed to dissolve the nitrite (but not more than that as to avoid dissolving too much NaCl) you will remove 75%+ of whatever amount of NaCl you still have left in your salt mixture. If I have calculated it all correctly you will have enriched the nitrite content by three orders of magnitude in five recrystallizations (or less!). If you start out with a NaCl:NaNO2 ratio of 100:1 you will soon have changed that to 1:10...
100:1 ? 25:1 ? 6:1 ? 3:2 ? 4:10 ? 1:10



Agni

  • Guest
using a retort
« Reply #22 on: October 25, 2004, 06:14:00 AM »
i really want to try this synth but i dont have a disstilation unit or the money to buy one. Could i use a retort instead of the "normal" flask/condenser method? they are a good deal cheaper.