zinc for levamisole/cocaine seperation

[daytryptr]

So after googling a way to purify cocaine and seperate any levamisole that may be present i came across this archived thread-

http://www.bluelight.ru/vb/threads/525731-Seperating-Levamisole-from-Cocaine

which had this bit of info in it-

Testing for levamisole should be possible using the already available sodium nitroprusside (simons reagent) the same reagent that is used to detect Meth and distinguish MDA from MDMA
levamisole should give a red colouration. I don't know what color cocaine gives but it is a tertiary amine and should be different.

some ideas for separation based on the chemistry,

the divalent sulfur in levamisole would not survive treatment with potassium permanganate solution. Cocaine does. if the oxidation product is a sulphonic acid then it is soluble in base whereas cocaine is not if the oxidation product is a sulphoxide then it will be insoluble in toluene which disoolves freebase cocaine.

The sulfur in levamisole will bind to zinc, lead, gold, nickel

I'm sure if some of the people here gave this some more thought there is an easy way to remove levamisole,
first off the method would involve freebasing the cocaine which removes most of the junk and the lactose, but not the levamisole then removing or destroying the levamisole then reconversion to the hydrochloride salt.

And nobody really elaborated on the zinc method of removing the levamisole by using zinc.

Some thoughts-

Dissolve your cocaine hcl in distilled water, add elemental zinc powder (just so happen to have some on hand). Let it react for a day or so.

Basify with calcium hydroxide, to precipitate calcium zinc hydroxide, the levamisole oxidation by-product, and cocaine base.

Dissolve what crashed out in anhydrous acetone, which theoretically should only pick up the cocaine base.

Add a bit of anhydrous methanol, and 30% hcl, to precipitate cocaine hydrochloride.

Any reason why this would not work, or if the levamisole oxidation by product as a base would be soluble in the acetone?

Or are there other ways to separate the cocaine from the levamisole after using zinc to oxidize the levamisole into a by-product?

 

[atara]

Incidentally, manganese is extremely toxic. Don't use KMnO4 to separate levamisole from cocaine unless you can recrystallize said cocaine several times to rid it of manganese -- you're better off snorting levamisole than permanganate, methinks.

Anywho, I don't think levamisole will react with zinc. The sulfur center will coordinate to Lewis acids, including anhydrous zinc halides, which is what that post probably meant. But that's not useful for your typical cocaine user.

So how to separate levamisole from cocaine? I can think of a couple ways to oxidize the levamisole thiopseudourea, which will result in scission. I strongly advise against attempting this chemical transformation if you do not have prior experience with chemistry! But cocaine should easily be separated from the scission products and recrystallized. Regardless, I don't feel that any method involving using a chemical to degrade levamisole would be safe for end-users who are not chemists.

Perhaps the right solvent will dissolve cocaine but not levamisole. Off the top of my head, maybe their hydrochloride salts exhibit differing solubility in dry propylene glycol? Or nuke's chromatography guide could be useful here.

Better to test for levamisole, and refuse to buy any cocaine that contains it! The market will get the hint soon enough. And if you are too hopelessly addicted to wait, you really do not need to be snorting the products of your own reactions!

 

[babylonboy]

Is cocaine usually recrystallised and extensively worked up after oxidation? KMnO4 is extensively used in SA in the production of cocaine, to remove other alkaloids from the product, and I doubt they're cleaning it up that much. Is this potentially a hazard all cocaine users need to worry about?

 

[Hammilton]

No, you need to first treat it with the KMnO4. I am more familiar with the risks of manganese than anyone, and I think that's the best way to go here. Manganese is easily removed, it just needs to be thoroughly removed as well.

 

[babylonboy]

Does that process of thorough removal happen at the point of production in South America though? Given the scarcity and value of solvents, I somehow doubt that they're doing an extensive workup after the oxidation of the base, do they not go straight from oxidation to crashing with HCl? Isn't this potentially a pretty serious hazard?

 

[Hammilton]

If it were you'd see rampant Parkinson's in cocaine users, early onset. It doesn't happen, so apparently not. Methcathinone users, in the other hand...