Easy Oxidation of THF to GBL

[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.