Sciencemadness Discussion Board

TfOH from Mesyl Fluoride + Fluorine

LSD25 - 1-4-2008 at 11:45

Some Japanese researchers, looking for a route to Li-Ion electrolytes have found that the treatment of Mesyl fluoride with fluorine (30% in N2) gives appreciable yields of trifluoromethanesulfonyl fluoride. If done without solvent at 20C, the conversion was 20% (80% recovery of Mesyl Fluoride) of which 30%+ was Tf.F.

If the reaction was done in perfluoromethylpentane, the conversion was 76% of which 87% was to Tf.F (64% overall).

I am assuming that Mesyl fluoride is accessible via Mesyl Chloride (+ KF?) and that Tf.F is able to be converted to KOTF via KOH (aq). If these are viable, then this may be a route to TfOH

http://www.4shared.com/file/42705569/41b980e5/Direct_fluorin...

Anyway, a lot of people here appear to be interested in strong acids, they do get stronger, but not by a whole lot.

What would be the better option for home use? The solvent-free approach at 20C looks useful - the main contaminants are CF4, CO2 & SO2F2. Would SO2F2 be hydrolysed to fluorosulfonic acid in the same way that SO2Cl2 is hydrolysed to chlorosulfonic acid?

PS This just barely is organic - thus I put it here:D

Nicodem - 1-4-2008 at 13:14

Using F2 for preparing TfOH starting from MsCl? A rational route for home chemists?
Surelly this must be the april's fools post, right? ;)

jizmaster - 1-4-2008 at 17:43

Yeah sounds fun! For those less suicidal/sociopathic how about this:

'sodium trifluoromethanesulphinate (CF3 SO2 Na), itself obtained from bromotrifluoromethane and sodium dithionite.'

http://www.patentstorm.us/patents/6506286-description.html

Bromotrifluoromethane is halon 1301 and seems to still be in use so it should be possible to somehow get hold of. And it should be possible to oxidise the sulfinate up to the sulfonate. The sulfinate can also be used to trifluoromethylate stuff apparently.

LSD25 - 1-4-2008 at 18:02

Quote:
Originally posted by Nicodem
Using F2 for preparing TfOH starting from MsCl? A rational route for home chemists?
Surelly this must be the april's fools post, right? ;)


Rational? What is rational about TfOH at the best of times? It is just that this route is marginally less suicidal than the electrofluorination route. That said, it is still fucking good evidence of insanity nonetheless:P I imagine you may be close to being on the money with your noting the date, but still someone may one day want the information...

I note however that there was extensive discussion on this site on how to prepare TFA & TFAA, so not everyone is sane enough to be scared off by F.

not_important - 1-4-2008 at 20:23

Halon 1301 has not been manufactured for over a decade, it's all reclaimed and recycled stocks now. If you own a system that uses it, you can get it refilled until stocks run out. If you happen to come across a Halon 1301 extinguisher, especially one that is filled, you might want to snag it.

LSD25 - 2-4-2008 at 06:43

Oh, here is an interesting route to MsCl:

http://ci.nii.ac.jp/naid/110003622483/en/ (hit the pdf button in the top right corner)

It uses the chlorination (firstly anhydrous, then water is added) of DMSO to give MsCl in 50-60% yield. Seems rather more OTC than any other synthesis I've seen.

Klute - 2-4-2008 at 08:31

Chlorination of alkylisothioureas, alkylthiosulfates, and alkylthiocyanates give good yield of sulfonyl chlorides. The isothioureas are simply obtained by refluxing thiourea in the corresponding alcohol. Direct chlorination of the salts or free compound in water/AcOH gives rise to the sulfonyl chlorides which precipitate out. See US2146744.

Thiosulfates also work nicely, although i don't think you can make them as easily with the alcohols, alkyl halides are used, but perhaps catalytic amounts of KI could help. Na thiosulfate is cheaper than thiourea. But short chained alkyl bromides are easy to make.
Chlorination of thiocyantes also produce CNCl, bromination would give the sulfonyl bromides and CNBr.
Reduction of the sulfonyl chlorides can give the disulfides or the thiols depending on the reaction conditions.

I would stay away from F2, even perfluorocompouds are bad as they easily release HF!

LSD25 - 9-4-2008 at 15:34

Thought this should be put here, simply to demonstrate the change in attitude of home chemists to HF/F:

Attachment: Thrilling.Stunts.with.HF.pdf (1.2MB)
This file has been downloaded 865 times

halogen - 9-4-2008 at 18:56

"I would stay away from F2, even perfluorocompouds are bad as they easily release HF!"
If it's perfluoro, where does the H come from?!:o Is teflon cookery to be avoided?

Klute - 10-4-2008 at 03:52

Quote:
:o Is teflon cookery to be avoided?
:D obviously not. I misexpressed myself.. I was thinking of trifluoroacetic acid and the like, not perfluoropolymers...

-jeffB - 10-4-2008 at 06:34

Quote:
Originally posted by LSD25
Thought this should be put here, simply to demonstrate the change in attitude of home chemists to HF/F:


I wonder how itchy that guy's hand got, after he held that glass in the HF fumes long enough to etch it? :o

stoichiometric_steve - 10-4-2008 at 07:19

Quote:
Originally posted by halogen Is teflon cookery to be avoided?


the residual PFOA/PFOS in pot PTFE coating is being released at temperatures lower than the decomposition point of PTFE.

i got bad rash twice after using a PTFE coated pan, now i stay away from it. forged steel pans have an antistick effect as well and you can take them to red heat...