Problem recovering amphetamine from a solution

[idunno]

I synthesized amphetamine freebase from P2NP using an electrolytic method according to US patent 1,879,003.
Everything goes well up to the point when I'm left with amphetamine freebase dissolved in H2SO4.
H2SO4 is slightly impure containing CuSO4 (can't get pure stuff as it's completely illegal here) but it shouldn't matter as from what I understand Cu is less reactive than hydrogen.
At this point Marquis reagent confirms there is amphetamine freebase in the solution.

Problem begins when the patent calls for neutralization of the acid in the solution by addition of caustic alkali.
Adding either NaOH or KOH destroys the product. Everything looks seemingly fine, Na2SO4 / K2SO4 precipitates and "amphetamine freebase" is collected as it's floating at the top.
Then I add 35% sulfuric acid to the "freebase" (35% contaminated with CuSO4 is best I can get) to make amphetamine sulphate, evaporate water, get white powder that's soluble in water, only slightly soluble in ethanol, insoluble in acetone (so everything like amphetamine is supposed to do) but Marquis reagent doesn't make the powder go yellow, there's no reaction to this reagent, which means it's not amphetamine...

I would be very grateful for helping me figure out where I'm going wrong and where is the problem that destroys my product.

 

[G.Patton]

Hi. It forms amphetamine sulphate instantly. It can't 'solve' amph.
What color it has? Marquis makes slight orange color with amph.
Have you tried to use phosphoric acid instead of sulphuric?

 

[idunno]

Thank you very much for you response G. Patton.

None. When I put Marquis on the white powder (final product) there is no reaction at all, the powder stays white.

But when it's still dissolved in H2SO4, after synthesis and before I add NaOH to get it out of the acid, I add Marquis to it and it rapidly changes color first to yellow then to orange. Which means the amphetamine is in fact there... up to this point.
So this way I know I do the synthesis correctly, what I can't do is get the thing out of the goddamn solution. I add NaOH to neuralize the acid it swims in, according to the patent, and it destroys my product...

I will try it, but I'm 99% sure it's not the fault of the CuSO4 contamination. If it was, the synthesis wouldn't work as it's literally swimming in a big amount of this contaminated acid during this entire electrolytic process. Then Marquis shows yellow/orange color no problem. Then I add NaOH and poof, no reaction to Marquis anymore.
Cu is not very reactive, less reactive than hydrogen, so there is no way it could mess it up.

This final product, the white powder, is very weird. It has all chemo-physical properties of amphetamine sulfate, except it doesn't dissolve in glycerol. Which also tells me it's not K2SO4 or Na2SO4 from the neutralization.

I suspect the problem might be that either Na or K displace one hydrogen atom in my amine as both these metals are more reactive than hydrogen. I also found that there does indeed exist a molecule like this, here: https://pubchem.ncbi.nlm.nih.gov/compound/49806546
There's very little info on it though.

But if it was indeed this problem, then how is it possible people add NaOH to their amphetamine all the time and it doesn't destroy theirs? I'm so puzzled, I can't understand why it works for others (and apparently the inventor of the patent too) but not for me.

Does NaOH need to be added all at once? I've been adding it partially, by small amounts, because H2SO4 + NaOH = a lot of heat, so I was cooling it down in the meanwhile (so the problem is not temperature decomposition either). But maybe this could be my problem? Maybe I should dump it all at once in there?
I dunno, I tried to add base to acid, acid to base, dilute base and base as a powder, same result each time, which is a useless white powder that does nothing.

Or maybe I add too much of NaOH? Or too little of NaOH? Would this matter?
Does it matter if I add it all at once? Does it matter if I add acid to base or base to acid?
Are there any other ways I could neutralize H2SO4 without damaging my amine so it doesn't get destroyed?

It should be so simple, it's just amphetamine dissolved in sulfuric acid. Why can't I get it out of it?

 

[WillD]

Try orthophosphoric acid for salt. How much percentage of alkali water solution is used? Do you cool the mixture before and during the addition? Are you using indicator paper or an electronic (and calibrated) pH-meter? The amount of alkali is determined by this, 10-12pH we need.

 

[G.Patton]

I don't think so. Maybe your solution was overheated during alkaline addition? You have to cool it down.

 

[idunno]

Thank you very much for you response too, William.

I will.

Saturated solution. Now as I think about it maybe I should add more dH2O to it so the Na2SO4 doesn't precipitate but rather stays dissolved in water. Maybe the problem is that amine sulfate crystals get trapped in Na2SO4 crystals and go down the drain with it... You might be onto something here, thank you! I'll see if it helps.

Yes I do cool the solution in ice bath and I do use indicator papers.

 

[idunno]

So I tried using more dilute NaOH solution (15%) and it didn't help. The recipe says I should see two layers but it doesn't happen, I'm left with a homogeneous aqueous solution.
It stinks like amphetamine, it must be there.

Guess I will try to add some diethyl ether now to see if I can extract it this way? Man I wish these patents were written more clearly and in depth.
Can't find the exact solubility of amphetamine freebase in ether though, other than "soluble" or "very soluble", so if someone knows how much I should use it would be helpful.
Does it even make sense or am I still doing something wrong somewhere else?

 

[WillD]

Add solvent for extraction or alcohol
Yes, good idea.
You can extract small portions, most likely there will be a yellowish base of the base. If it is not, the extraction finish. Either we take an excess of ether and evaporate after.
Everything makes sense

 

[idunno]

So the ether extraction did work so this problem has been solved, unfortunately my yield keeps being extremely poor, can't get beyond 10%... Guess I will make another thread to discuss this issue to keep things clean. Thank you everyone for help once again.

 

[MadHatter]

Congratulations for expertly solving the extraction issue! Sorry for being thick, but what was the actual solution? Was it:
1. Use dilute NaOH
2. Extract with ether?
Have you tried doing the electrolysis without the sulphuric acid though?

I wrote in your other thread, but I suspect your low yields are due to not running enough electricity through your solution. From the description you gave you would need to push A LOT of electrons through that bad boy. Like several DAYS of several amps. And keep the voltage fairly low to not overheat it.
But I'd LOVE to see a detailed write-up of your experiment!