Author Topic: Easy Oxidation of THF to GBL  (Read 31760 times)

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TrickEMethod

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Re: Easy Oxidation of THF to GBL
« Reply #60 on: January 04, 2002, 12:39:00 PM »
Sorry for the delay... I have had some equipment adventures.

I should be starting the reaction, using h2o2 as noted, tonight.  Do I still need to allow 16hrs for stiring?  8hr or so would be more convenient, but if that is likely to hurt yield or reduce the usfullness of the results, I'll run the full 16hrs.

I'll check back before I start...


And on the eight day, God created Meth...
... and hasn't done much of anything usefull since!

spectralmagic

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Re: Easy Oxidation of THF to GBL
« Reply #61 on: January 05, 2002, 08:27:00 PM »
Although very much the newbee, Swim was feeling inspired by the sheer awe of the Hive, and has also been without the beloved nutrient for some time, so he decided to try something...

- THF distilled from vinyl flooring glue (the only other ingredient listed was methyl isobutyl ketone which boils at 117C, so Swim felt he could trust the distillate collected at 65-70)
- 100g of ice chunks in a 250mL flask, to which 10g of THF and 10mL of 31% HCl was added
- 25g of 65% Ca(ClO)2 was added slowly, letting it thoroughly disperse before adding more.  The solution took on a yellow tint early on, lots of Cl2 produced, and the ice chunks melted pretty soon.
- Swim decided to let it stir in an ice bath...  but forgot to turn it on.  For about 30 seconds the solution bubbled unnoticed, until Swim turned the stirrer on...
- Swim went to sleep, but first added plenty of ice to the bath.  9 hours later everything returned to room temperature (probably sooner).  There were practically no solids in the flask.  Still yellow.
- The solution was brought to a light boil, then filtered (Swim figured he needed the practice, and it did remove some crud)
- Swim was certain he could smell GBL...
- 8g of NaOH were added, and the clear yellow solution turned into a cloudy dark orange mess within seconds.  This was stirred for the better part of 2 hours.
- Now the solution contained lots of chunky solids, as well as lots of fine particles
- Swim checked the pH... over 12.  Figured he might as well bring it down now, he'd read here somewhere that GHB would "burn" when it was dried if basic.  It took about 4mL of 31% HCl to neutralize.
- Now the solution was dark brown, practically black, and all the solids were clumped together
- Swim heated and filtered this mess...  solution was still dark but no longer cloudy...  and it had a peculiar odour, somewhat like a cross between caramel and that smell the grocery store's fresh produce section has...
- The water was driven off in an oven set at 110C... leaving behind gummy dark-brown solids that took an hour to scrape off the dish
- The solids were dropped in 70mL of methanol (Swim figured about 12g of GHB was in there somewhere, 6mL of methanol per gram)
- Swim stirred and stirred...  the methanol took on the dark-brown hue, lots of white salt and some black lumps did not dissolve, and were filtered out.
- A lot of acetone was added, and lots of fluffy solids appeared...
- The solution was filtered for the last time, this time finally keeping the solids...  but damnit, the colour stayed with them!
- The solids were dried, then taste-tested.  Ugh.  Salty Swim can handle, but these were very bitter.  Besides, the colour was all wrong, and the smell/taste overall quite different from what Swim was used too...  the end product was not consumed.

Discouraged, yes, but Swim will try again.  Perhaps with NaBr + Oxone next time... and probably extracting the GBL with DCM and perhaps distilling before reacting with the NaOH.  Or maybe just drive off the DCM, Swim is unsure if nasty peroxides coexist with the GBL after extracting...

To Bee, or not to Bee...  ;-)

pharmy

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Re: Easy Oxidation of THF to GBL
« Reply #62 on: January 13, 2002, 04:42:00 PM »
Hello everyone!

I was also looking in mechanism of preparation of gama-butyrolactone with bromate and hopping chlorate would do the same thing. I made some researching and found out that trichloroisocyanuric acid is used for oxidizing of ethers and cyclic ethers to esters and lactones. In this abstract they claim that also hypochlorus acid can be used for ox. of the THF :) :) :)  I have two references but I can't get them. Maybee someone could use this

Tetrahedron Lett. 1968, page 5819; Tetrahedron 1971,vol 27, page 2671

Abstract (from 1971)

The study of the oxidation of symmetrical and unsymmetrical ethers in the direct conversions of ethers to esters by trichloroisocyanuric acid is reported. Initial work indicates that there is a selectivity in the oxidation of unsymmetrical ethers and that Newman's "rule of six" may be an important factor in this selectivity. Hypochlorous acid which is a simpler positive halogenating agent and which could actually be the functioning oxidizing agent generated by hydrolysis of trichloroisocyanuric acid is not effective as a general oxidizing agent or substitute for trichloroisocyanuric acid. although it does oxidize diethyl ether and tetrahydrofuran.

Bouth hypochlorus and trichloroisocyanuric acid (pool desinficiens)  are very OTC. Soo any suggestions????
:)

foxy2

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Re: Easy Oxidation of THF to GBL
« Reply #63 on: January 14, 2002, 09:18:00 AM »
UTSE and you will find extensive discussion of THF--> GBL using Ca or Na hypochlorite.

I hate my government, does this mean I'm a terrorist??

Cyrax

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Re: Easy Oxidation of THF to GBL
« Reply #64 on: January 19, 2002, 04:06:00 AM »
Rhodium, this is a very nice procedure, absolute kitchen chemistry.  Congratulations !!!

Could you tell me something about the pharmacology of NaGHB?
What is the dose?  Is it toxic?  What are the effects?  Is it good stuff for recreational use?

Thx

Rhodium

  • Guest
Re: Easy Oxidation of THF to GBL
« Reply #65 on: January 19, 2002, 05:30:00 AM »
You will find all such info about GHB you need on www.erowid.org

riobard

  • Guest
Re: Easy Oxidation of THF to GBL
« Reply #66 on: February 01, 2002, 09:14:00 AM »
SWIR decided to try out the same proceedure that you have described and got almost exactly the same result on his first time out. There is nothing half assed about the reactions in themselves, but the clean-up is hard to do kitchen-chemistry style. You may want to note a few of these things:

-An obvious indication of complete reaction between the THF and ClO- ions is an absence of the green color from the chlorine. I'm sure you probably already knew that. Just in case, bring your mix to reflux after you're confident that it's safe to stay at room temperature.  Hold it there for a while, maybe 30 minutes or so. At least that's the time it took for SWIR's mix to lose any hope of green tinge, even though almost none of it was detected at room temperature. One less impurity to worry about.

-An obvious problem in the end product of the whole course is the impurities. The easiest way is to distill out your GBL. Distillation always will yield the cleanest result, which is why it is standard to do so in multistep synthesis with liquid intermediates. I think it is ok to simply evaporate off the THF and move on, but only if the entire solution has been filtered until it is very clean, and I know full well that this isn't an easy task. Get out all of that inert crap and the CaCl2. All of it. If you're distilling, you just need to get most out, and the amount of residue left will just be what you have to clean out of your flask. Then you have weighable, clean GBL, and no real need for recrystallization at the end of it all.

-It is also standard(IMHO) to reflux a GBL NaOH reaction mix in 40%H2o-alcohol to make the final product. This presents problems for anyone without purified GBL in doing it with ease, because of the unknowns of GBL content and necessary NaOH. Again, distillation is reccommended. If it can't be done, your mix will have to be heated for a few hours(i may be shaky on the time here) to ensure complete reaction. And after that, by not knowing your yield in GBL, you have to compensate by adding acid or base in neutralization of either putting too much lye in or too little. This ends up making more sodium chloride salt, adding to salt taste, and fucking up your product, also making it bad for your electrolyte balance in your body.

    So get a distillation setup, or avoid pool chlorine, or do a bunch of reactions until you get a feel for it. The way I see it, it'll cost you less to get equipment you need anyway than to spend time and energy working for nothing. I know that SWIR spent from 5P-7A working out his first hypochlorite runs due to evaporations. Not worth the time or money if the end result is failure.

Good luck to all in their ventures, and if anything is incorrect above please don't hesitate to correct me.

TrickEMethod

  • Guest
Re: Easy Oxidation of THF to GBL
« Reply #67 on: February 14, 2002, 05:11:00 AM »
I profusely appologize for the MONTH of delays getting this reaction started.  I was determined to use some new homebuilt equipment instead of the lab glass I spent so much money to aquire.  Go figure...

So after my pc controlled stirrer was finally working, the peristallic pump started just jacking the h2o2 up and down in the tubing... after that was fixed the tubing broke due to oxidation by the reagent, so I had to order new tubing, which was a different size, so I had to rebore the pump...  AARRRGGHHHH!!!

Anyway, it is running right now.  But I am having to add the final 15g or so of h2o2 by hand because a plastic pully came loose from a shaft.  Oh well, the automated cooling controller and stirrer are working perfectly.  I even testing the cooling and stirring failure alarms that I hooked up through the X10 to flash the kitchen, dining room and bedroom lights if anything goes wrong.

So far I havn't seen the cooling pump run much at all, only twice in the last six hours.  And then it was only for a few seconds which spiked the temp right down without much opposition.  I don't think my reaction is all that exothermic, but I am running it quite slow.  And I understand that the reaction excelerates as it progresses by building up Br2.  On the positive side the color turned to a quite noticable pink or orange after a couple of hours, which I assume is due to the formation of Bromine?

One question...  Instead of extraction with Methylene Chloride, can I directly distill and keep the >200C runoff?  That would save me cracking open my short supply of Cloroform, which is the closest I have to MC.

Let me know...
TrickE

FYI, the reaction setup is a jacketed flask built into a 2" thick Lexan containment enclosure with complete PC control and monitoring, all built OTC except the flask.  I would post some photos, if their is some way to upload them without regestering a anonymous web site.  If their is interest, I can provide construction tips for the metered dispencing pump, cooling setup and pc control hw & sw (1 transister, 1 relay, 2 resisters, 1 doide, 5 wires per controlled motor, software is in VB).

And on the eight day, God created Meth...
... and hasn't done much of anything usefull since!

TrickEMethod

  • Guest
Re: Easy Oxidation of THF to GBL
« Reply #68 on: February 14, 2002, 04:16:00 PM »
Well, I made a mistake on the scale up math.  Between adding the first reagents and the final h2o2, I stopped scaling up 5x.  So I went back and added more NaBr, H2S04 and H2O2 all over again after I would have been about done.  So I don't know what that is going to do.  Whatever the outcome, I will fix my pump and run the reaction again tomorrow.

The reaction got more exothermic after I added the proper ratio of reagents, but still nothing big deal.  My cooling setup never let it get above 22.1c, and I had it set for 22C, so it wasn't working too hard.

The color is quite striking, deep, deep, deep orange.  Like when you crash out for 48hrs of sleep involentarily but wake up barely needing to piss because you were so dehydrated you should have been in the ER.  That kind of orange, but with a different smell.  The wallpaper is still on the walls...

I and stil curious about directly distilling instead of extraction with solvent first, and I also am curious whether the lactone would react badly with stainless?  If not, I have an interesting idea for a distilation setup.

Thanks
TrickE

And on the eight day, God created Meth...
... and hasn't done much of anything usefull since!

Osmium

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Re: Easy Oxidation of THF to GBL
« Reply #69 on: February 15, 2002, 04:21:00 AM »
You cannot distill the whole load. You have to extract first.

I'm not fat just horizontally disproportionate.

moo

  • Guest
THF oxidations
« Reply #70 on: May 13, 2002, 03:12:00 PM »
There should be no danger of peroxides in the Fe2+/H2O2 reaction as both Fe2+ and Fe3+ ions react with them. In fact, ferrous salts can be used to efficiently remove peroxides from ethers. Acc. Chem. Res. 8, 125 (1975) is an interesting article about this so-called Fenton's reagent including kinetic data on the reaction with THF which makes me think that the major by-product would be succinic acid.


J. Am. Chem. Soc. 89(14), 3550 (1967), titled The Mechanism and Synthetic Utility of the Oxidative Cleavage of Ethers by Aqueous Bromine is also interesting. In this paper the researchers reacted various ethers with bromine at pH 5 in the dark (to prevent light-catalyzed free-radical halogenation), and whaddaya know, THF:Br2 ratio of 1:4 yielded 100% GBL. The procedure, which seems to differ from the information in the table, is as follows:

"Purified tetrahydrofuran (1.0g, 0.014 mole) was treated with 12.0g  (0.0705 mole) of Br2 in 15ml of water. The reaction mixture was stirred at 0° and the contents were monitored by pms spectroscopy. At the end of 2 days the bands of tetrahydrofuran had completely disappeared and only the bands of gamma-butyrolactone were present."

Not that it would be convenient to use elemental bromine, but it could mean that the THF wouldn't get brominated and the H2O2 could be added faster if the reaction was to be protected from light. And now, I begin to wonder whether the oxidation of Br- with H2O2 would produce those radicals after all. Back to the library ;D .


Chromic

  • Guest
more thf->gbl
« Reply #71 on: October 02, 2002, 12:47:00 PM »
Well, I went and looked at J. Am. Chem. Soc. 89(14), 3550 (1967). The table in the article says 1:4 THF:bromine, but the procedure reads exactly as moo stated (1:5). Weird.

And the weird thing is with the Tetrahedron ref where BrO3 is used, it seems to me to mean that only 3 molecules of Br2 is needed for each THF. (ie each NaBrO3 is capable of making 3 Br2)

I'm confused. Won't there be an excess of bromine left over at the end of the rxn, even with the lowly 1:3 ratio?

Btw, you guys do a good job at finding refs! I went through SciFinder and couldn't find anything else that was of obvious interest on the thf -> gbl conversion. I'm somewhat happy to see everyone here does a good job researching, but I was also disappointed with the lack of literature that I found.


GC_MS

  • Guest
small sidenote
« Reply #72 on: October 02, 2002, 12:58:00 PM »
A small sidenote about THF. I heard about a suicide attempt with THF. The man that tried to commit suicide was taken up into the hospital, and his blood + urine content were closely monitored. After 2 days, the man all the sudden started to hallucinate! Surprise surprise, the man had high levels of GBL and GHB in his blood. He died at day 4.
There are indications that the human body can oxidize THF to GBL, which can be converted to GHB. This just as a sidenote; please DO NOT DRINK THF!!! I clearly said he died  :P .

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moo

  • Guest
And about the Fe(II)/H2O2 method
« Reply #73 on: October 02, 2002, 01:22:00 PM »
It's been a while, but a couple of test runs was done almost according to JP53087347, which was deciphered a bit to find out that the amount of water in the example seems to be 100g for 0,5 moles of THF. I think the scale was 1 mole: 0,2 moles of FeSO4 was dissolved in 200g water and mixed with 1 moles of THF, then H2O2 was added dropwise with overhead stirring. The yield was never good because the temperature wasn't kept inside the limits required in the patent and the project was abandoned because of other reasons. In the end of the last run there was a GBL left, maybe a 10% yield. Furthermore, it is easy to have a runaway reaction as it is easy to add H2O2 so that it accumulates and when the temperature starts to rise, it starts reacting and so on. This might well work as stated in the patent if the temperature is controlled appropriately. Needless to say, the reaction is volumetrically more efficient than the Br-/H2O2 method.

Antoncho

  • Guest
Ahem... Excuse me?
« Reply #74 on: December 10, 2002, 09:53:00 AM »
I confess i haven't been following this thread for a while but have you seen this?

Patent US3074964



It's a direct oxidation of THF to GBL with bromine or chlorine, the max yield being 77%

Looks quite interesting, huh?



Antoncho

moo

  • Guest
Yes
« Reply #75 on: December 10, 2002, 11:22:00 AM »
I hope you didn't miss

Post 381459

(moo: "THF -> GBL patents etc.", Methods Discourse)
 ;) .

DCM001

  • Guest
How are they distilling the product, what...
« Reply #76 on: April 16, 2003, 08:01:00 AM »
How are they distilling the product, what temperature, etc?
Is it possible to use a Buchi distillation unit...?
And when extracting with DCM and drying with MgSO4, does that mean we are passing our extract thru the MgSO4?


Bwiti

  • Guest
THF/H2O2/FeSO4
« Reply #77 on: May 12, 2003, 03:06:00 AM »
"There should be no danger of peroxides in the Fe2+/H2O2 reaction as both Fe2+ and Fe3+ ions react with them. In fact, ferrous salts can be used to efficiently remove peroxides from ethers. Acc. Chem. Res. 8, 125 (1975)"

  With that in mind, after the THF/H2O2/FeSO4 has reacted, could the mix be staight-up distilled at normal atm, without extracting with a non-polar solvent? Maybe filter it before distilling? :P


Aurelius

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Peroxides
« Reply #78 on: May 12, 2003, 01:21:00 PM »
hey bwiti, give the reaction mixture a wash with Fe+2 solution in water.  separate and dry.  Now distill.  Do NOT distill to dryness.  Is GBL water soluble?

fierceness

  • Guest
AFAIK, GBL reacts with water (in equilibrium)...
« Reply #79 on: May 12, 2003, 02:00:00 PM »
AFAIK, GBL reacts with water (in equilibrium) to form GHB.. i think the ratio of GBL/GHB is 70/30, but i'm not sure.