Distilling THF from pipe cement

[Hansje]

I have always assumed that distilling the mixture without adding reductant is quite safe due to the considerable amount of water in there. Fate hasn't proved me wrong yet   , but don't take my word for it, I'm just guessing.
You'll need to add some peroxide scavenger if you want to store your THF after distillation. Not bisulfite solution if you don't want to distill again.
Hansje high in proteine and fibre!

[Chromic]

It seems that a sat sol'n of bisulfite forms a separate layer, and so, that's fine if I'm just using the impure THF for oxidizing with NaOCl. I might stall a bit on this procedure... I'm not as excited to oxidize THF as I once was... especially when all the dangers are taken into account... I've done some crazy stuff (like making Et2O)... but the thought of an ether and an oxidizing agent initimately together is really starting to scare me.  

[Antibody2]

antibody usually has abit of water in the flask when distilling ethers (can never distill to dryness) on a water bath. Then add a couple chunks of NaOH or dry EtOH to the receiver for storage. No explosions yet .

[weedar]

I would love to see OTC GHB from this,but of course,safety
first!

Weedar
Weedar contains 2,4-D dimethylamine salt,apparently

[Chromic]

I awoke today, and looked at my amber glass bottle with THF in it. It was biphasic and filled with crystals! For a second, I thought "shit, this is really fucking bad..." Then a split second later, I realized, oh yeah, I had a added bisulfite to it. Looks like some of the cyclohexanone and acetone crashed out of the THF.    I was just hoping for it to remove the oxygen and prevent formation of peroxides... oh well, onto distillation. (I'm not going to filter out the crystals) I want to get this isolated soon and just store it over a bunch of bisulfite... my interest is gaining in other projects right now. (especially finishing the write up of the peracetic method in DCM as I hasn't done enough testing with asarone and the peracetic and never given a formal write up... and also polishing up a cold water extract on codeine that happens to also remove most of the caffeine... plus changes to the methyl man document... etc etc)

[Chromic]

Run down of the results happened:

1. added 3/4 volume of water to pipe cement
2. filtered with cotton, using rubber gloves squeezed out rubber in the cotton.
3. saturate the aqueous extract with salt
4. took off the top organic phase
5. add ~1/3 volume of sat bisulfite sol'n & stir slowly overnight (forms a separate layer)
6. fractionally distill the solution that should now contain the bisulfite adduct (insulate column, go slow). collect between 64-68C. (true bp=66C)
7. check density of distillate, 0.86 (true density=0.888)
8. stored with a bit of sat bisulfite sol'n until use (two separate layers form)

I seemed to have recovered about 30% of volume of the pipe cement as THF.

[Chromic]

Going close to the ratios in

Post 326569

(Chromic: "Calculations for THF =)", Methods Discourse), I took 5ml 10.8% bleach (5.7g, 8.3mmol, 1.9 eq) and added 0.35ml THF (0.32g, 4.4mmol, 1 eq). I wanted to use an excess of THF to judge the completion of the reaction on the disappearance of chlorine.

Fearlessly, I added all 0.35ml of THF at once. Nothing happened. Allowed it to sit... ahh, it's getting warm. Then it starts to cool about 10 mins later. The solution is cloudy and smells like chloroform. There are small droplets of an organic phase at the bottom of the test tube.

I tested the sol'n for chlorine by adding a drop of the sol'n to phenolphtalein. It went pink (indicating basic conditions) and stayed pink (no chlorine).

Does THF smell like acetone? What tests can I do to verify that what I have is actually THF?

[Chromic]

(takes ten steps back) wait a minute... does anyone have any reason to believe that hypochlorite can oxidize THF to GBL in any other conditions than acetonitrile/AcOH? (

Post 3958 (missing)

(Fuchem: "Oxidation of THF to GBL from Tetrahedron Letters", Chemistry Discourse))

It appears to me that THF is undergoing a haloform reaction... which is mighty useless to me.

[Chromic]

I'm out of ideas. Maybe I'll just drink it as is, my metabolic pathways will take care of turning the THF into GHB, just as they turn GBL into GHB ever so conveniently...


</joking>

[Antibody2]

What tests can I do to verify that what I have is actually THF? aren't ethers supposed to explode when you add some H2O2?

sorry, you were talking to yourself dude

[SpicyBrown]

Does THF smell like acetone? What tests can I do to verify that what I have is actually THF?

No, THF and Acetone smell pretty different from each other. Don't quite know how to describe the THF smell, except maybe along the lines of a sickly Diethyl Ether-like scent. It REALLY stinks in SWIM's opinion.. If you get a big enough whiff (Not recommended, of course) you can taste the shit in the back of your throat, nasty indeed.

SpicyBrown

[Chromic]

This stuff smells like a nasty version of acetone, maybe a bit like diethyl ether... but the smell is not as heavy or as prevalent. Ether stinks up the entire lab when it's used, this stuff doesn't seem so bad. I'm completely convinced now, that THF can't be made by aqueous oxidation using hypochlorite. I believe it can happen using acetic acid and acetonitrile... but I really doubt Cheapskate's THF -> GBL thread.

I too got something salty from the rxn, but I can say, without a doubt, that it was salt.    I should add some GBL and hypochlorite to see if it forms a chlorinated layer as well, I've got little doubt that it's easily chlorinated.

[weedar]

Is this the end of theoretic OTC GHB?
(at least for now?)

Weedar
Weedar contains 2,4-D dimethylamine salt,apparently

[Osmium]

I think people should concentrate on the MBrO3 oxidation of THF. Once that reaction is completely understood and gives consistent yields the bleach version will work much better.
I'm not fat just horizontally disproportionate.

[riobard]

The cheapskate write-up is nowhere as simple as it reads. After swim's toying with batch sizes, parameters, cooling methods, and the all too famous billowing white solids that can't be vac filtered (without special fritted disks or what the fuck ever else one might use besides qualitative grade filter paper), the two of us can only conclude that we should have saved the ACS THF for lithium aluminum hydride reductions like for 2-cb.
     Aqueous methods are wasted time. If i see pool shock again  before i die it will be too soon.
     I'd put a little more faith in that whole procedure if someone could give us a formal write-up INCLUDING A BIOASSAY of the final product. If I'm wrong about what I did, I'd surely welcome a correct path.

Cheapskate, I mean no disrespect. Your contribution in the OTC quaalude synth was, and still is, awesome.

[Chromic]

Sounds good, but I'm not sure how many people have access to OTC access to BrO3 (not me). KBr and H2O2, OTOH, are easier to get a hold of. Is there any way to oxidize KBr to KBrO3 using H2O2?

[Osmium]

UTFSE for 'bromate', this has been discussed ad nauseum.
KBr can be used to make Br2, which is the active ingredient in the bromate oxidation.
I'm not fat just horizontally disproportionate.

[Chromic]

How do I do this? Would dripping H2O2 into a solution of KBr in water (since bromine is the catalyst, and it could be recycled, this could likely be reduce a bit) with THF and H2SO4, be a smart idea?

Can you give me a balanced set of equations so I can figure out the stoichiometry (ie how many Br2 is required per THF) and an idea of the excess (5%? 10%?) to use so that I could put together a method? Sorry for not using the search engine, but you could have brought me up to speed in half a second.  

[Rhodium]

All the reaction equations are actually present in the original paper we discussed a few months ago:

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

- not too common in journal articles nowadays, but in this case they were all there.

Entropy just isn't what it used to be.

[Chromic]

I see they used 1 mol BrO3- and 1 mol ether with 1 mol acid in 1L water. How many Br2 is this equivilant to?

The images seem to indicate 1 mol BrO3 can turn 5 Br- into 3 mol Br2? Would this mean translate to using 3 mol Br2 for 1 mol ether? Or just 1 mol of Br2 as is shown in the rxn mechanism for the Br2 oxidation of THF.

Does anyone have an experimental of aqueous Br2 oxidizing THF?