Safe evap temp of pseudo/eph HCl in water

[biotechdude]

Hey all...

If one had say 5g of pseuso/eph HCl in about 1 litre of dH2O; what would be an efficient (and safe) temperature strategy to evap the water off at?

Now Swix is aware that most do it at low heat on a hotplate with a fan, or in a warm fan-forced oven at about 60`C solution temp.

However, Swix is also aware that at seemingly safe temps...the pseudo can scorch when water is almost gone.

So Swix wants to evap off the water under vacuum in a pyrex pot..and wants to know what temp u could safely heat (and evap) the solution too under vacuum (so it obviously boils at a lower temp than 100`C).

Also in his thoughts is that when there is lots of water u could crank the heat up more...but then u would have to cool it when approaching skinning as the evap dish will be absorbing and retaining heat quicker than the water is dissapating it (through evaporation)..and hence the hot pot surface may scorch the dry pseudo at the end. (doh!)

Any comments, ideas or tips in bed?

[gryphon]

That's a lot of water.
A fan over the top and low heat, but towards the end or first sign of crystal formation, turn heat off or remove from heat.  The pyrex glass still has lots of heat in it.  Continue using the fan, and if you have one section of the base of your container 'crackling' back, slush over it with the surplus pools of water.
Or you could start off with a higher temperature and then reduce it when it gets to a more predictable stage of completion.

[SHORTY]

How did you end up with so much water?  Anyway if it were me i would heat on a hotplate to 90C in a visionware saucepan with a fan blowing right across the top of the pan but not into to it. 

A few hours later when it nearly all the water has evaporated and no water could bee seen flowing under the skin when the pan is tilted, i would pour about 50-100ml of dry acetone into the saucepan and swirl the contents, and finally decant the acetone into a clean glass jar, bottle or whatever.

If i timed it right and didn't wait too long before decanting the acetone, i would have completely dry meth hcl within 5 minutes due to the saucepan being warm enough to quickly dry the salt but not nearly warm enough to scorch it.

The acetone would be kept and accumulated either for emergency situations or reprocessing as it would contain a small amount of meth.

[biotechdude]

The large ammount of water arrives from the steam distillation of ephedra freebase; not pills, as raised the concerns.

Swix will try under vacuum at 90'C; and will cool and acetone flash at near-dryness... just what he had in mind anyway.

Thanks

[SHORTY]

Or did you already acidify it?

In my previous response i was thinking you had meth rather than eph.  However, i would still do it the same way. 

Using a compressor from a ref as a vacuum i have boiled water at about 55C.  You might run into problems with bumping though.

[biotechdude]

Yes shorty, the fb/water distillate was pH'd to 6 then evap'd. 

A good alternative is pull the fb into a dry np and gas...but that takes alot of time effort and money when a simple titration and water evap can produce the same results. 

Vacuum will bee produced from a water aspirator with tap water being blasted through it at full blast.  I think stay around 80'C under vacuum until nearing dryness then back off and let cool and become anhydrous with acetone.

I think thats safe...

[SHORTY]

I have always wondered what fb eph looks like when distilled.  Is it oil like with meth?  If you put it in the freezer will the crystals form in the water as it cools? 

If it is like meth after distillation then it would be on top and most of the water could bee drained prior to acidifying couldn't it?

I have tried several times to steam distill pseudo but have not been successful. 

I have had some very dirty fb pseudo which i put in a filter and poured at least 2 liters of water over it during the course of a day and finally got it clean.  The water didn't seem to dissolve much if any of the fb pseudo.

[biotechdude]

"...I have always wondered what fb eph looks like when distilled.  Is it oil like with meth?  If you put it in the freezer will the crystals form in the water as it cools?..."

From Swix's experience, the fb eph comes over undetectable to the eye (in a lieberg); and condenses into a clear solution with a slight oily tinge on the top (but the fb oil is dispersed throughout the entire solution).  Hence, the water cannot be separated; which is annoying.  I have put the pH6 distillate in the fridge for storage for a little while; but never to near freezing.  It would bee so good if the pH6 distillate could just cooled to near freezing and the salts collected via filtration; but alas, my guess is it wont work like that.

This is unlike meth-fb that is thick fatty oil (mmm) that is visible and sits on top of the distillate water. 

From

https://www.thevespiary.org/rhodium/Rhodium/chemistry/meth.ephedrine.steam.html

"...A separation of ephedrine from the amphetamines seems possible if a steam distillation as mild as possible is used to isolate the amphetamines. Then a forced steam distillation can be used to separately collect the ephedrine. ..." 

Post reaction, Swix distills his meth by adding some clean sand and gently boiling (bringing over meth-fb/water).

When Swix steam distills eph/pseudo he uses a 'steam-dream' unit that directs steam into the bottom of the flask and causes rigorous agitation (and the liberation of fb eph).  Yields have been lower when boiling it over on its own. 

Care needs to be taken with foaming as small increase in temp and/or agitation causes the whole caboodle to foam into the recieving flask.  Thats not cool...

[SHORTY]

That was the main problem i had when trying to distill pseudo from the pills.  No matter what i did the foam wouldn't let up.  But i may have distilled some and didn't even know it as i was expecting to see something similar to meth when distilled.

[Newton]

... SWIN has done the evap process at 100 °C several times, as well as under slight vacuum (water bp 60 °C). No ill effects where observed when doing the evap at atmospheric pressure.
This was done with aqueous l-ephed.Hcl solution (from steam distilled Ma Huang, basified to ph 6) in a 1l rb flask, with a liebig condenser. SWIN uses a closed setup even when separating the ephed from the water at atmospheric pressure, for reasons of smell containment (boy that stuff has an ugly stench).

This is continued until most of the water (>90-95 %) has made its way into the receiving rb flask, along with most of the stenchy stuff from the initial solution (probably some volatile aromatic oils from the Ma Huang), so you're left with an almost odorless, slightly viscous solution.

The last part of the evaporation is then done in a glass dish, sitting on a hotplate at 50 °C, optionally blowing with a fan over in it.

[biotechdude]

Swix was looking to speed up more large scale evaporations...but from everyones valued info; the following seems the best..

Put eph Hcl/water into sealed pyrex pot under vaccum and heat until boiling (about 70'C).  Then when going viscous, remove from high heat and vaccumm and place in fanforced oven or on hotplate at 50'C.  Then eat.

Conversely, Swix is curious about pulling the eph fb/water into a np (xylene) and then adding a little water and titrating to pH 6 and then evaping as per above (when combining runs).

Now Swix is unsure about the dynamics of a/b extraction.  Does the ammount of np required correlate to 1) the ammount of fb in solution, or 2) the total volume of solution it is contained in.

If it was 1), then if one had 5g fb in 1+ltr of water, then could one add say 100mL of dry xylene, shake like crazy for a few minutes, then add 20mL water and titrate and evap?

If it was 2), then alot of xylene would be consumed and this would suck.

Also, would multiple pulls with the np bee required?  Swix is curious as evaping is slow as fuck, and he has xylene at his disposal...but if its more trouble than a simple evap; he will just stick to that (with the mentioned improvements).

[SHORTY]

After distillation, what is the ph of the water/eph solution?  In my opinion the amount of fb determines the amount of xylene required regardless of the amount of water.

Why not try it on a small amount and see if it works?

[biotechdude]

pH is about 10.  Can be higher if more caustic is used or lower if more water is bought over at the end.

Should Swix add some concentrated NaOH solution to the distillate to raise the pH to 12+, and hence enhance migration to the np.  He will test soon.  Is the key to migration the up/down shaking? Or what if it was put on a magnetic stirrer?

Re Foaming - Swix uses a 2ltr twin neck, filled with pH12 ephedra extract.  The total solution contained is never more than about 800mLs.  Then a splash head is also used and the thing is watched carefully.  You cant stop the foaming; but a setup like this allows 'room' for it to happen.  Also, it foams hardcore at the start, then settles down ALOT. 

Perhaps SHORTY u really did collect good distillate (but didn't recognise it); perhaps just a 'roomier' flask will accomodate the foaming (and remember the foaming subsides after a little while).  I think someone said to "add a few drops of blah blah" and it settles it even more. Can't remember; perhaps some anti-foam compound?

[Newton]

Unfortunately, option 2) is the case. The amount of fb that will be extracted, is proportional to the ratio of extractant volume (in this case xylene) to the volume of the solution containing the desired fb.

For example, if the l-ephed fb would be equally soluble in both water and xylene, extracting with twice the volume of the aqueous solution (2 parts xylene, 1 part water), would yield 66% of the fb in the xylene layer - this is the absolute maximum after sufficently mixing the layers. Doing the smae process again would get you 66% of the remaining 33% fb (thats 22% of the original fb amount), increasing the yield to 66%+22%=88%.

In reality, the extraction yield is also proportional to the ratio of the fb solubility in water to the solubility in xylene. (Anyone got the solubiliy values at hand?).

Extracting meth fb from water with a np solvent would require only a fractional volume of the original solution, since the meth fb is almost completly insoluble in water, while it is very soluble in xylene.

But since l-ephed fb (contrary to d-pseudopfed) is quite soluble in water, it would probably take several extractions with at least equal, or even larger volumes of xylene, to get the mjority of the l-ephed fb out of the water.

Which is pretty impractical, unless one got easy access to large quantities of high purity xylene, and is not concerned about handling several litres of a volatile, toxic, flammable, and environmentallly hazardous substance...

[SHORTY]

I would have thought that adding more naoh to the solution after adding xylene would work.  But i have never used ephedrine so i can't say for sure.  I also didn't know that fb ephedrine was as soluable in water as it is in xylene.  If that is the case then it probably won't work.

If you do test it please post your results good or bad.

[biotechdude]

Thanks Newton; exactly what Swix had thought...

"...and is not concerned about handling several litres of a volatile, toxic, flammable, and environmentallly hazardous substance... "

= Several hundred litres; no thanks