[curiouscat]

What are good solvents for KMnO4 to be used as an oxidizing agent? My substrate is a water immiscible liquid and the idea is to see if reaction rates can be hastened by using an organic dissolved KMnO4 (as opposed to a water solution).

KMnO4 seems unstable in many typical solvents.

Ideas?

[discodermolide]

Try a phase transfer catalyst and stir like hell.

[antimatter101]

Get a crown ether like 18-crown-6, quadternatery ammonium salt, and some benzene/pyridine solvent (derivatives also work) and mix them all together. Add your KMnO₄ right after, and stir. It should completely dissolve.

You never used crown ethers in your entire life? That's disappointing.

[curiouscat]

You never used crown ethers in your entire life? That's disappointing.

Sadly true.

But thanks for the tips.

[curiouscat]

Try a phase transfer catalyst and stir like hell.

Thanks @disco!

[discodermolide]

I think crown ethers may be too expensive for curious, and too toxic. I think he is really large scale!
Phase transfer cats. are certainly cheaper and easier for him to handle.

[curiouscat]

I think crown ethers may be too expensive for curious, and too toxic. I think he is really large scale!
Phase transfer cats. are certainly cheaper and easier for him to handle.

My bad. Yes, @disco brings up an important point that I always forget to mention:

This isn't a lab prep but an intended commercial process  with target volumes of several tens of tons per month of a not-very-high-value product (~$5-7 / kg).

So, yeah, can't really go for very fancy / nasty or expensive ingredients.

[discodermolide]

Several tons per month, now that is a decent scale!

[curiouscat]

Several tons per month, now that is a decent scale!

tens of tons....   

[discodermolide]

Even better, tons is small scale stuff.
At least you see what you get, more than can be said for the poor Academics with their mgs!

[curiouscat]

At least you see what you get, more than can be said for the poor Academics with their mgs!

One reason I switched tracks after my post doc. 

Most of  the stuff I do is quite low brow science not of any fundamental interest though.

[discodermolide]

Must be of interest to someone with tens of tons a month.
Anyway high or low brow it's still interesting and each has its own particular problems.

[curiouscat]

Must be of interest to someone with tens of tons a month.
Anyway high or low brow it's still interesting and each has its own particular problems.

True! Thanks for your tips as always. I'm going to try some TBAB / Aliquat. Might be challenging finding a PTC that KMnO4 won't oxidize away.

[discodermolide]

May make TBAB permanganate?

[antimatter101]

-18-crown-6 solvates the potassium ion in KMnO₄ while the quad. ammo. salt solvates the MnO₄^- anion, basically.

If the crown ether is that expensive, then don't buy it. (My recommendation) Instead, why not make some yourself? You could use Williamsom ether synthesis, though chances are there will be multiple products.

Toxicity can be handled with some antidote (if possible), some PPE, and a fume hood. In factories people carry around hydrofluoric acid while whistling, and people almost never get hurt. Why so afraid of crown ethers?