Easy Oxidation of THF to GBL

[Rhodium]

To a stirred mixture of 7.2g (0.1 mol) tetrahydrofuran (0.1 mol) in 100ml water there was added 15.1g of sodium bromate and 13.6g (0.1 mol) potassium hydrogen sulfate. External cooling was necessary to keep the temperature of the solution between 25-30°C. Stirring was continued for 16 hours at room temperaturem, after which time all the THF had been consumed. To quench any excess bromine formed, acidic sodium sulfite solution was used [bisulfite should work just as good]. Thus 140-150ml of a 10% solution was added and 13.6g (0.1 mol) potassium hydrogen sulfate. The reaction was cooled and extracted with 5x30ml dichloromethane. The combined organic layers was dried over MgSO4 and the solvent removed under vacuum. The residue was distilled to give gamma-butyrolactone in 73% yield (bp 204-205°C).

The procedure is extensively optimized, and most part of the article deals with the mechanism and kinetics of this particular reaction.

Reference: Tetrahedron 56, 1905-1910 (2000)

[Prdy2GO]

Yes! I like I like it a lot quite intreging I must say.
Do you think that it can be scaled up say 10 or even a 100 times with all the same values?
Don't look at me I didn't do it!

[Rhodium]

I believe it is perfectly scalable, the only thing you should watch out for is possible overheating of the reaction mixture just after the bromate is added (perhaps slow addition is a good idea at larger scales). The authors reccommend to use a reflux condenser to avoid loss of THF if the cooling is not strong enough. Try the reaction out at this scale, and report back to us how much heat is evolved.

I would also say be careful to not skip the bromine neutralization step with sulfite. It is not good if you carry bromine over into your product. Potassium hydrogen sulfate is easily made by yourself by mixing equimolar amounts of KOH and H2SO4 in a water solution, and evaporating the water. Sulfite/bisulfite is OTC.

[foxy2]

Hmmm wonder if Sodium Iodate would work also??
Do Your Part To Win The War

[Osmium]

Well, from an economic standpoint it might be more interesting if chlorate will work. Or if that reaction can be made catalytic in bromate. chlorate/H+, H2O2/H+ or oxone maybe? Sounds like it might work.

I once did some analytical chemistry on phenols and phenolethers, and I remember that I used iodate which is a strong enough oxidiser to destroy the aromatic ring of methoxybenzenes and convert the CH3O into formaldehyde.

[Rhodium]

According to the article I took the synthesis from, the actual oxidizing agent is bromine. The role of bromate is just to re-oxidize bromide to bromine again.

[Osmium]

Bromine??!  

Well of course, that makes sense!

5 Br(-) + BrO3(-) + a couple of H(+) -----> 3 Br2 + 3 H2O !!

Somehow bromate oxidises something and gets reduced to bromide. This bromide reacts with the bromate synproportionating into Br2, which will do the the oxidising business from now on. In every catalytic cycle more Br2 is produced, that's why they use so much Na2SO3 in the end! I was wondering why that was necessary. Makes sense now!

Well, if that's the mechanism then it will be possible to make this procedure a catalytic one, and to run with NaBr/H2O2 instead! Or NaBr/oxone! Or NaBr/persulfate!

Hoooray!

Damn damn damn! I already see the headlines of the  newspapers:
"Banned date rape drug use on the rise again ; hits streets with a vengeance. How to protect YOUR CHILD! Read more on page 3..."

[terbium]

"Banned date rape drug use on the rise again ; hits streets with a vengeance. How to protect YOUR CHILD! Read more on page 3..."
Funny that you mention that. There was a full page article in the Nov. 26 Los Angeles Times titled In The Grip Of GHB.

Some quotes from the article:

"This is the most addictive drug I've ever seen," says Dr. Stephen W. Smith ... "People are desperate to get off of it because it's destroying their lives," he says ...

Patti Trovato-Ragano of Naples Fla., believes that her son ... might still be alive if he had received proper care for his GHB addiction.

Former LAPD Det. Trinka Porratta says statistics underestimate the problem.

and so on ad nauseum. If it bleeds, it leads.

Well, now that the "crack baby" epidemic has been debunked, it looks like the people who make their living fighting drugs are looking for a new demon.

[Prdy2GO]

Thanks Rhodium.
Swim was thinking she could try it as written first and she said she will let me know how it goes. Just so happens she has all the components Prdy2go so no need to make the potassium hydrogen sulfate. One question did come up about acidic sodium sulfide is this the same as sodium sulfide reagent? Or perhaps Na bi or metabisulfate is just as good? thanks
TTFN
Don't look at me I didn't do it!

[Rhodium]

NOT sodium sulfide (Na2S)!

The reagent they are using is sodium sulfite (Na2SO3) which they acidify, to get a solution of H2SO3 (essentially an aqueous solution of SO2). Using sodium hydrosulfite (aka bisulfite aka metabisulfite) will also give the same H2SO3 upon acidification.

[Osmium]

Well, in the end it doesn't really matter, all these sulfides/sulfites will reduce the Br2.

[Prdy2GO]

Rhodium,
Where can the reference be found online? or perhaps you could post it kind sir?

Don't look at me I didn't do it!

[Rhodium]

I will post a PDF of the article soon, as soon as my favorite reference-gatherer downloads it from his Tetrahedron Online account.

http://tetonline.com/

[Prdy2GO]

Thank you
And yes SUIFITE of course that is what I wah thinking but not typeing. Sorry for the typos that may apper in this on as it is dark in here.
SWIM at the keys now.
Started the reaction early today about 58F in the lab looking over the glassware and due to size needed decided to scale up a bit ease of finding the results is what was on the minde at the time. I am going to list this out as the steps taken. I was not privy to the reference so I may have done this all wrong this may be an example of how not to do this.
Expecting a exothermic reaction72g of THF were placed in a 2l FB beaker and 1l DH2O precooled this in the fridge placed on the stirrer was a stainless steal lab bucket the beaker placed inside and several packets of blue ice and water 3" egg stirrbar set on #6 (cornning 10x10 620) began adding the powered sodium bromide a little at a time noted temp at 15C no real change in temp so I dumped it all in (151g.) Began the addition of the potassium hydrogen sulfate much the same way the temp began to drop to 9c then as low as 4c. after ab hour I removed the cooling setup took the temp probe out and checked to make sure it was working correctly. It checked out ok slowly came up to RT and is still spinning set on 9 now. It has been 5 hrs and the grinding of the stirrbar have long gone looks thicker and is sn opalesent in apperence.
Any one care to coment on the steps taken does this sound right still wondering why is was indothermic?
Don't look at me I didn't do it!

[Rhodium]

Are you still making typing errors, or did you use Sodium Bromide (NaBr) instead of the required Sodium Bromate (NaBrO3) in the reaction?

[Chemikaze]

Hahahaha way to go:)
Cool
Everybody in the house with a half an ounce
Not weed I meant coke dumb ass sit down!

[Prdy2GO]

Nope I used sodium bromide oops. Guess I start over? LOL ithink it's kinda of funny see what I mean about the dark it is hard to read in this cave.
Don't look at me I didn't do it!

[Rhodium]

Yup, you need to start over. Better luck next time!

[Osmium]

No!
Do not start over. Drip in some H2O2. Or add some oxone or peroxodisulfate. Or calcium hypochloride. Prove me right.

[foxy2]

Electrochemical synthesis of g-butyrolactone from tetrahydrofuran.    
Kirsanova, A. I.; Smirnova, M. G.
Elektrokhimiya  (1978),  14(4),  627. Journal  written in Russian.   
Abstract
A method is described for the anodic oxidn. of tetrahydrofuran (THF)  [109-99-9] to g-butyrolactone  [96-48-0] in a KBr soln. with Na2SO4 as a supporting electrolyte on a Pt electrode at pH .apprx. 1.  The anodic efficiency reaches 98% when a diaphragm is used.  THF is oxidized indirectly by BrO3- formed during the oxidn. of Br-.  At higher pH (6-7) the oxidizing agent is BrO- formed at the anode and the current efficiency decreases due to the simultaneous formation of oxybutyric acid.
Do Your Part To Win The War

[foxy2]

This is essentially the same of more work for GBL, however some of the other uses might bee of interest.

Use of ruthenium tetroxide as a multi-purpose oxidant.
Berkowitz, Lewis M.; Rylander, Paul N.   
J. Am. Chem. Soc.  (1958),  80  6682-4. 

Abstract: The scope of the oxidation reactions of RuO4 (I) was investigated.  I was prepd. by the slow addn. of N NaBrO3 to 4.37 g. RuCl3 (contg. 18% H2O) in 80 ml. refluxing 0.5N HCl, while I and H2O distd. into an ice-cooled receiver.  I (55% yield) was then decanted and dissolved in CCl4 to give a deep red soln.  Alcs. were oxidized rapidly by I to carbonyl compds.  Thus, I in CCl4 was added to 1.50 g. cyclohexanol in 10 ml. CCl4 at 10-15° (ice-cooling was required).  After standing overnight at room temp. the mixt. gave 2.18 g. RuO2 and 93% (based on I) cyclohexanone.  Similarly, the following compds. were prepd. from the corresponding alcs. in the indicated yields: l-menthone, 96%; 3-cholestanone, 49%; BzH, 90%.  n-C6H13OH, however, gave only 10% n-C5H11CO2H even with excess alc. trans-1,2-Cyclohexanediol in H2O gave 15% dione (or oxo-alc.).  Aldehydes were oxidized rapidly to acids to give 33% BzOH and 30% n-C6H13CO2H.  Olefins were oxidized to aldehydes with C-C bond cleavage,(hmm...piperonal from piperine or from isosafrole? in contrast to OsO4 which gave diols.  Thus, cyclohexene gave 10% adipaldehyde and 1-octene gave 12% n-C6H13CHO and (presumably) CH2O.  The low yields were possibly due to the difficulty in sepg. the products from RuO2.  Me cyclopropyl ketone reacted little, if at all, with I.  A unique reaction of I was the oxidation of ethers to esters.  Thus, 2.55 g. Bu2O and 1.91 g. I in CCl4 gave a quant. yield of PrCO2Bu,while tetrahydrofuran gave a nearly quant. yield of g-butyrolactone which could not be oxidized further.  An attempted oxidation of ethylene oxide at 0° in CCl4 to an a-lactone (II) gave only a polymer, possibly derived from II.  Tetrahydrofurfuryl alc. gave a compd., possibly an aldehyde lactone, forming a dinitrophenylhydrazone.  Although esters were stable to I, amides were oxidized to imides.  Thus, 1.33 g. g-butyrolactam and 1.69 g. I gave 49% succinimide.  N-Heptanoyl-n-hexylamine similarly gave an imide.  C6H6 and EtCHMePh gave immediate reactions with I to yield unidentified carbonyl compds.  C5H5N, (PhCH2)2, Ph3CH, tetrahydronaphthalene, 1-O2NC10H7, (PhN:)2, PhC.tplbond.CH, and (PhC.tplbond.)2 also gave immediate reactions but no isolated products.  Slower reactions of I with Am3N, Et2NH, and piperidine apparently gave amides, while n-C6H13NH2 apparently did not.  Ru is less volatile, less toxic, less expensive, and more readily available than Os. 
Do Your Part To Win The War

[Osmium]

Os is confused.

Is it bromate as foxy2's ref says or Br2 according to Rhodium's article that oxidises the THF?

Prdy2GO: add H2O2 or another oxidiser anyway.

[Prdy2GO]

Thanks Os but this was one of the only times I actually through something out. I am not able to find my NaBROMATE so I know you were thinking of using something else and I would like to try something else as well what would you suggest? BTW was my procedure ok besides the wrong Na that is?
TTFN
Don't look at me I didn't do it!

[foxy2]

Tetrahedron Letters
Volume 42, Issue 34
(2001) Pages 5833-5836

Solvent free permanganate oxidations

Abstract
The oxidations of organic compounds by permanganate under solvent free conditions have been studied. Thiols and primary aromatic amines undergo oxidative coupling reactions to give disulfides and diazenes, respectively, sulfides are oxidized to sulfones, primary and secondary alcohols are converted to aldehydes and ketones, 1,4-diols and cyclic ethers give lactones and arenes are oxidized to the corresponding -ketones. The experimental procedure is simple and the products are easily isolated in good yields.

Best results are obtained when KMnO4 is first mixed with copper sulfate pentahydrate (or a 20/80 mixture of copper sulfate pentahydrate and alumina) to give a reagent that has previously been used extensively as a heterogeneous oxidant in inert solvents. The reductant is then added dropwise while the solid oxidant is tumbled using a magnetic stirrer. Most reactions can be carried out at room temperature; however, improved yields for solid reductants are obtained when the reaction temperature is near or above their melting points. Some reactions benefit from the application of additional energy in the form of microwaves.[8 and 9] Product isolation can be achieved by washing the spent oxidant with an organic solvent, which can subsequently be recovered by simple distillation. Many of the reactions are nearly quantitative giving products of relatively high purity.

Preparation
The oxidant is prepared by grinding equal amounts of potassium permanganate and copper sulfate pentahydrate in a mortar until homogeneous or by adding a concentrated aqueous solution of potassium permanganate to alumina, giving a paste which is then ground with an equal amount of copper sulfate pentahydrate. Reductant (2 mmol) is added to a portion of the oxidant (~4 g) in a 25 mL round bottomed flask and stirred magnetically until TLC analysis indicates a completed reaction. The residue is then washed with a minimum amount of solvent (methylene chloride, hexane and/or ether). Distillation of the solvent gives a product that is of acceptable purity for most purposes. If greater purity is required, the product can be distilled or recrystallized.

The following two procedures were performed at room temperature useing the oxidant KMnO4/Al2O3/CuSO4·5H2O.

1,4-butanediol for 14 hours yeilds 95% GBL

tetrahydrofuran for 6 hours yeilds 70% GBL
Do Your Part To Win The War

[Osmium]

Well, I have a few grams of RuCl3 at home, but since it fell in my lap by divine inspiration I can't comment on its price right now, except that it is probably VERY expensive by most bee's standards. Sounds like it will work in catalytic amounts and bromate or other oxidisers can be used with it (I don't see any reason why it shouldn't work). But what solvent? Chlorinated hydrocarbons will not dissolve most oxidisers.

[foxy2]

Osmium
I would trust Rhodiums reference for the mechanism.  They are forming bromate which seems to bee equivalent to adding bromate, i would assume. 

Here is what they say in Rhodiums ref

The fact that the rate of oxidation accelerates during the
process, strengthens our assumption that oxidation with
bromine is the main operating mechanism. When bromine
oxidizes THF, bromide is formed. Bromate can react with
the bromide in the acidic medium to yield bromine.

If we assume that 2.5 molecules of Br2 react with THF according to Scheme 7 to yield five bromide ions, these
ions will then react with one molecule of bromate to
produce three molecules of bromine. Thus, in this cyclic
process in which we start with 2.5 and produce three
molecules, which can now further oxidize the ether, we
gain half a molecule of Br2. In each oxidative cycle we
produce an extra half a molecule of bromine and the result
is acceleration of the oxidation reaction. This is a typical
autocatalytic process.

We suggest the following general scheme (Scheme 9) to
describe the oxidation process of ethers with bromate
salts: a slow initiation process, in which Br2 is formed
followed by an accelerated propagation process.

In conclusion, our data on direct oxidation of ethers with
bromate point towards bromine as the main active oxidant.
Bromate itself is responsible only for the initiation step and than plays the role of a co-oxidizer or bromine supplier.

Do Your Part To Win The War

[foxy2]

The yeilds are not stellar but.....

g-Butyrolactone from tetrahydrofuran.    
Hara, Hiroshi.  (Japan). 
Japanese Patent  JP  53087347  19780801

Abstract: THF (0.5 mol) and 0.1 mol FeSO4 in H2O was treated dropwise with 1.05 mol 30% H2O2 at (less than)30°C and the mixt. stirred 3 h at 30°C and 8 h at 45°C to give 61.6% g-butyrolactone. 
Do Your Part To Win The War

[foxy2]

Novel oxidation of tetrahydrofuran to g-butyrolactone with peroxyphosphoric acid.    
Ogata, Yoshiro; Tomizawa, Kohtaro; Ikeda, Toshiyuki.
J. Org. Chem.  (1980),  45(7),  1320-2. 

Abstract: THF was oxidized with peroxyphosphoric acid (H3PO5) at 25° to give g-butyrolactone in 80-90% yield based on the decompd. H3PO4 neat or in MeCN.  Little effect of O and radical inhibitors on the yield suggests that this reaction proceeds via an ionic mechanism involving g-hydroxybutanal and a-hydroxytetrahydrofuran.  Similar oxidn. of Bu2O gives the corresponding ester in a moderate yield and that of tetrahydropyran gives a trace of the corresponding lactone. 


Preparation and estimation of peracids and peroxides.     Afzal, S. M.    Fac. Pharm.,    
Pak. J. Sci.  (1980),  32(3-4),  201-4.

Abstract: HOOSO2(OH) was prepd. by reaction of ClSO2(OH) with H2O2 in isoamyl alc., by reaction of K peroxydisulfate with BCl2, by boiling Ba peroxydisulfate in H2O, by anodic oxidn. of H2SO4, or by bubbling SO3 through H2O2 soln.  Peroxydisulfuric acid was prepd. by electrolysis of H2SO4, hydrolysis of K peroxydisulfate, or by reaction of ClSO2(OH) with H2O2.  HOOPO2(OH) was prepd. by reaction of P2O5 with H2O2 in MeCN.  Peroxydiphosphoric acid was prepd. by reaction of H4P2O7 with H2O2.

Novel decontamination agents. Destruction of organophosphorus and sulfur toxic agents by monoperoxyphosphoric acid.    
Lion, Claude; Hedayatullah, Mir; Pires, Fabrice; Charvy, Claude; Briand, Sylvette; Magnaud, Gilbert; Delmas, Gerard; Sentenac-Roumanou, Et Henri.  
Phosphorus, Sulfur Silicon Relat. Elem.  (1996),  118 89-94.
 
Abstract: H3PO5, monoperoxyphosphoric acid easily prepd. by the reaction of H2O2 with P2O5 in acetonitrile, is a very good decontamination agent.  The destruction of toxic S and P agents is completely achieved in very short time. 

Do Your Part To Win The War

[Osmium]

Oh my!
Peroxyphosphoric acid works! Sounds like the beloved oxone is worth a try too!

We used to clean clogged fritted glass filters by pouring some THF into them, and adding fuming HNO3. Once the acid was in you better hurried and closed the fume hood because after a few seconds this mixture started giving off NOx fumes like crazy. Really makes me wonder what intermediate was formed in that reaction  

[Osmium]

> THF (0.5 mol) and 0.1 mol FeSO4 in H2O was treated
> dropwise with 1.05 mol 30% H2O2 at (less than)30°C and
> the mixt. stirred 3 h at 30°C and 8 h at 45°C to give
> 61.6% g-butyrolactone. 

Fe(2+)/H2O2 is a known radical starter for aq. medium. I don't know, makes me kinda nervous because of possible peroxide formation. I hope the other 40% of THF didn't turn into evil peroxides  


> Thanks Os but this was one of the only times I actually
> through something out. I am not able to find my NaBROMATE
> so I know you were thinking of using something else and I
> would like to try something else as well what would you
> suggest?

Repeat what you described up there using 103g NaBr instead of the 151g NaBrO3. Once this works we might be able to even reduce the amount of NaBr further. In case you don't have any KHSO4 you can simply use half the molar amount of H2SO4, or a little more than that. Then drip in 1mol H2O2 wjile stirring. 30% H2O2 is preferred, if all you can get is 3% then reduce the amount of water in the reaction accordingly. If there's undissolved NaBr don't bother, it will eventually dissolve.

> BTW was my procedure ok besides the wrong Na that is?

Don't cool it right from the beginning, try to start at about 20°C, and once you see that there is a positive exothermic reaction start cooling as necessary to keep the temp in the desired range.

[foxy2]

"I hope the other 40% of THF didn't turn into evil peroxides "
Yea it would suck to blow yourself up!!!  

Could you not just wash out any peroxides with water?
Flood post reaction mix with water and extract out the GBL with DCM, you will also get the THF but I think the peroxides will stay in the water.  Just wash the DCM extract a few times.  Anyone know for sure?

Then dry the DCM/THF/GBL and distill it to purify the goods.  But don't distill to dryness, just to bee safe.


Do Your Part To Win The War

[terbium]

Organic peroxides are generally soluble in organic solvents.

[Prdy2GO]

Thanks Osmium,
Started all over this time half scale of the previous post.
currently stirring in H2O2 one drip about every 2-3seconds the temp has been at 15c for the last 10 hours adding H2O2 raised the temp 1c at about 10ml addition point. I an useing ~.50 mole (57mml)30% H2O2 I looked up in Vogels about the explosive tendencies and how a protective shield should be used. So I moved it next to a sliding glass door checked and set the fire extinguisher near by and put on my leather jacket and black neoprene gloves;just in case...
Don't look at me I didn't do it!

[Prdy2GO]

    
Poster: Osmium
Subject: Re: Easy Oxidation of THF to GBL

"Well, I have a few grams of RuCl3 at home, but since it fell in my lap by divine inspiration"

Per haps we share some divine spirit as It just so happens that 50g of rubidium chloride manifested in my presence. I had been wondering what it wanted to be when it grew up. I dont want to waste it the gooing price is 354.00 as listed in something I had retail mom and pop shop. Is there a reference on line or could some one post it please? I think I will do a search on Rubidium and see what I come up with.
Thanks
TTYL

Don't look at me I didn't do it!

[foxy2]

Ru is Ruthenium, and it is not in any way similar to Rubidium except for the spelling.
Do Your Part To Win The War

[Rhodium]

RuCl3 is a very good safrole isomerization catalyst (see my isomerization FAQ).

[Prdy2GO]

Can Fe2SO4 be used insted of FeSO4 what is the diff? one II the other III
Don't look at me I didn't do it!

[Bwiti]

  Anyone here ever try oxidising THF with dichromate/H2SO4, then extract with ether?
  Split a piece of wood and I am there. Lift a stone and you will find me.

[Rhodium]

Bwiti: Do you have any references for that? The biggest problem with all these oxidations is that you don't want to oxidize the GBL further to succinic acid, which happens to some extent with all the oxidants tried for this reaction.

[Bwiti]

"Bwiti: Do you have any references for that?"

  No, it was just an idea. I'm completely miserable, because a grignard that I attempted was a complete failure for no apparent reason. At the moment, life fucking sucks, and I was looking for an easy way to create GBL, so I could get blissed out of my fucking mind!
  Split a piece of wood and I am there. Lift a stone and you will find me.

[Prdy2GO]

Dichromate? is this not toxic? How would you go about the work up distill?
Don't look at me I didn't do it!

[Rhodium]

CONVENIENT SYNTHESIS OF LACTONES BY THE REACTION OF DIOLS WITH N-HALOAMIDES
Kondo, Shuji; Kawasoe, Shinya; Kunisada, Hideo; Yuki, Yasuo
Synth.Commun. 1995, 25 : 5 719-724.

Abstract
Reaction of 1,4-butanediol or 1,5-pentanediol with N-haloamides such as N-chlorosuccinimide, N-bromosuccinimide, N-bromoacetamide, isocyanuric chloride, and N,N-dichlorobenzenesulfonamide under mild conditions gave gamma-butyrolactone or delta-valerolactone, respectively, in high yields.

[Rhodium]

I now have the original article for the sodium bromate oxidation online:

https://www.thevespiary.org/rhodium/Rhodium/archive/thf2gbl.pdf

I bet somebody out there is able to fine tune it with all the reaction mechanism information that is included.

[Osmium]

And let me repeat this once more:
the oxidant in this reaction is Br2, not NaBrO3. So it should be able to make this reaction work with NaBr/H2O2.

[Chromic]

To remove peroxides wash with a solution of sodium metabisulfite.... it will oxidize to sodium bisulfate and destroy the peroxide.

[Prdy2GO]

Thanks Osmium,
Sodium Bromate is this not the same as BORAX??
"20 mule team power" OTC
Don't look at me I didn't do it!

[Rhodium]

No, borax is sodium borate. Big difference.

[Osmium]

No!!! Completely different animal!
And you don't need bromate. Bromate is unusual, special order only and expensive. NaBr is OTC and quite cheap.

[Prdy2GO]

WTF is this shit I can not find this stuff localy. Is there another name for it OTC or other wise.
Don't look at me I didn't do it!

[Prdy2GO]

This is common OTC if this is not it could you give me the CAS?
Thanks
Sodium Tetraborate Decahydrate CAS # [1303-96-4]
Synonyms: Borax; Borates, Tetrasodium Salts, Decahydrate; Sodium Diborate Decahydrate; Tetraborate, decahydrade; Disodium tetraborate decahydrate; Sodium borate decahydrate; fused borax; borax glass; fused sodium borate; borax decahydrate; Borascu; Borax (B4Na2O7.10H2O); Boricin; Gerstley borate; Sodium pyroborate decahydrate; Sodium tetraborate decahydrate (Na2B4O7.10H2O); Solubor; SODIUM BORATES
B4H20Na2O17
381.4

Don't look at me I didn't do it!

[Rhodium]

The CAS No for Sodium Bromate is 7789-38-0

[Osmium]

If your supplier can't get you any NaBrO3 when you tell him you want sodium bromate then I doubt the CAS number will help him finding any. Sodium bromate is the globally accepted English name for this substance.

[MTM]

the oxidant in this reaction is Br2, not NaBrO3. So it should be able to make this reaction work with NaBr/H2O2.

Has somebody already tried this?

M T M

[TrickEMethod]

Os, give this a look and see if it is what you had invisioned.  Now that the wifes passed out, dogs run off, kids are in protective care and the neighbours are all dead, its finanlly quite enough around here to do some chemistry! 

I have:
  all necessary glass(flasks, columns, condensers...)
  vacumme & dessicator
  mag stirrer
  temp controller
  shielded hood
  12 glow-n-the-dark napkin holders commemorating Elvis, the man behind the fetishes

I Also have:

   THF              - lab grade
   NaBr             - pool store
   H2SO4            - autoparts store battery refill
   Sodium bisulfite - OTC, don't remember where
   MgSO4            - OTC, epsome salt

I am missing the CH2Cl but I do have CHCl3(lab grade), will that work? 

To a stirred mixture of 7.2g (0.1 mol) tetrahydrofuran (0.1 mol) in 100ml water will be added 10.3g of sodium bromide and 11g (0.1 mol + a bit) sulfuric acid. External cooling may bee necessary to keep the temperature of the solution between 25-30°C. Stirring will be continued for 16 hours at room temperaturem, after which time the THF should bee consumed. Sodium bisulfite(140-150ml of a 10% solution) and 11g (0.1 mol + a bit) sulfuric acid will be used To quench any excess bromine formed.

The reaction will be cooled and extracted with 5x30ml chloroform. The combined organic layers was dried over MgSO4 and the solvent removed under vacuum. The residue will be distilled to give unconcious-highschool-chearleeders in 194% yield (bp 204-205°C).


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

[terbium]

No! Did you read the previous posts? If you have sodium bromide (NaBr) then you also need hydrogen peroxide.

[TrickEMethod]

My bad, I have the H2O2 written down.  I just fucked up on the post.

I have lab grade 30%, and will add ~34g dropwise. If what I wrote down is correct.

With all the mention of Br being the active agent, I have lab grade Br2.  It tastes pretty bad, but I guess its still ok.
And on the eight day, God created Meth...
... and hasn't done much of anything usefull since!

[Rhodium]

One point I believe is important in this reaction is that the concentration of free bromine is always kept low. Therefore the direct addition of elemental bromine is not reccommended, and instead it is slowly made in situ from other agents (like potassium bromate or KBr/H2O2).

[TrickEMethod]

One last question.  Is anything likely to be liberated that would fall into the "Bad" category.  "Bad" as in reeks, kills or attracts ninjacopters with narcobeamification goggles?  Either way I will probably pipe everything down the gass trap.

I was a A-100% doubter on the marco-chopper talk, but I've had two flyovers at coencidental timing in the last 10days.  I had never seen a chopper fly low over our neighborhood ever.  Fuck that, now I put most everything down the sewer.  So now I only have to worry about the submarines patrolling down steam.

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

[Rhodium]

Some bromine and HBr may form, but if you are not letting the mixture heat up too much, they should not voilatilize so much that they present a problem for you.

[Osmium]

The original reaction is:

BrO₃^- + 5 Br^- + 6 H^{+ __}> 3 Br₂ + 3 H₂O

This means:

1. the reaction is auto-accelerating (in each reaction sequence 20% more free Br₂ is generated)
2. for each mole of BrO₃^- present 3 moles of Br₂ are produced during the reaction

Since in my proposed variation the following reaction takes place:

2 Br^- + 2 H⁺ + H₂O₂ ^__> Br₂ + 2 H₂O

you have to add 1 mole of H2O2 for each mole of Br₂ you want to generate in situ.
Add 3 equivalents H2O2, not just one. Drip it in slowly over several hours.

[TrickEMethod]

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]

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]

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]

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]

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]

You will find all such info about GHB you need on www.erowid.org

[riobard]

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]

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]

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]

You cannot distill the whole load. You have to extract first.
I'm not fat just horizontally disproportionate.

[moo]

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 .

[Chromic]

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]

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   .
WOMAN.ZIP: Great Shareware, but be careful of viruses...

[moo]

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]

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]

I hope you didn't miss

Post 381459

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

[DCM001]

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]

"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?

[Aurelius]

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]

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.

[moo]

The Fenton oxidation of THF to GBL involves both Fe²⁺ and Fe³⁺ species not least because it is a catalytic amount of the iron salt. Now after checking the references I have on hand on decomposition of peroxides by iron, they say that hydrogen peroxide is decomposed by acidic solutions of Fe³⁺, but say nothing about THF hydroperoxide (Acc. Chem. Res. 8, 125 (1975)). On the other hand the ref. that explicitly discusses the decomposition of THF hydroperoxide by metal salts mostly discusses the reaction with Fe²⁺ (Bull. Chem. Soc. Japan, 36(5), 527-30 (1963)). So I'm not so sure anymore because there is a risk I don't want to get blamed for if the information was incorrect. It could possible that undecomposed hydroperoxides remain after the reaction, but I guess it is unlikely. These free-radical reactions are chaotic, hard to predict, produce various byproducts and considering the possibility of an explosion it might just be wiser to add a little ferrous sulfate later on to take care of the bogies.

Distilling the reaction mixture by itself would be at least partly a steam distillation... I remember it is a method that has been used in isolation products from horrible reaction mixtures containing iron salts, yes it is really a dirty reaction. I think adding FeSO4, distilling, extracting the goodies from the distillate with DCM, drying the DCM, evaporating the DCM and then vacuum distilling the GBL from the residue for further purification would be in order.

[Bwiti]

>isolation products from horrible reaction mixtures >containing iron salts, yes it is really a dirty reaction.

  Probably won't be as messy as with iron/nitrotoluene.