First LWR, major PH issue

[jammin]

Did my first LWR with 2.5g E, let it react about 27-30 hrs before i pulled it off.

Added equal amount of water into the rxn flask
Filtered the solution

Washed with NP three times (toulene).
Based the reaction fluid to 13 - 14 (bad ph papers)

Added NP for extraction of the amines, stirred and let sit 10 min. Repeated this three times.

Combined NP layers and washed with dh2O + NaCl

Added dh2O and started titration.
By mistake a large amount of HCl was used.

Swim has read something about "dont worry about this, do not try to neutralize it with NaOH, you'll just end up with a massive amount of salt."

So swim started to evaporate. He noticed HCl fumes was very stron and after the evaporation he got a powder with distinct yellow color.

He realized that "this cant be good" and added some dh20 and NaOH to try to neutralize it ("hell, the byproduct will only be NaCl anyway", he thought)

Now the solution is slightly basic and swim is out of crappy ph-papers (and off to buy an electronic PH reader).

So he wonders...

Whe the dish has evaporated will it be meth.HCl and NaCl or something else?

And if something else is it possible to save it?

Swim is esp. worried about sollution beeing sligthly basic so it knocked of the HCl for the meth molecule..



Please advise... and thanks again....

[Osmium]

What you have now is a mixture of NaCl and meth freebase.
Dissolve it all in water and a little HCl, wash it once with your favorite NP, add more NaOH to make it basic again and extract the freebase. In other words, repeat the A/B.

May I also suggest you try gassing this time. Put a spoonful or two of HCl into a soft PE plastic bottle, squirt some conc. H2SO4 (2ml or so) on it, immediately close the bottle with a stopper with some tubing attached, and bubble the HCl gas through your extracts containing the freebase. Squeeze bottle to help in gas generation. Be careful about suckback. This works extremely well.

[jammin]

Can i just add some HCl to mace the meth.hcl again?

I dont want to run a new AB again unless its absolutly required.

I dont mind some extra NaCl in the mix, its just for personal use anyway...

[Ganzas2003]

first my very first doubt:

whats the accurate way of calculating how much HCL is needed to salt the expected meth? grams to ml ratio...or like the chems like:

how much moles of HCL are needed to salt x moles of meth freebase?

anyway acetone really does a good job here...keep the acetone...evap it and it will smell HCL badly..not to mention the yellowing.

[Osmium]

> how much moles of HCL are needed to salt x moles of meth freebase?

Obviously the ratio is 1:1.

> Can i just add some HCl to mace the meth.hcl again?

Yes you can, but you will overshoot the right pH, ending up where you started (plus a little extra salt).

> I dont want to run a new AB again unless its absolutly required.

Quit bitching and just do it, you're only about an hour away from the clean end product.

[jammin]

>> I dont want to run a new AB again unless its absolutly >>required.

>Quit bitching and just do it, you're only about an hour >away from the clean end product.

Yes, but i am just a little intimidated, cause i dont want fuck it up again.

How much HCl should i use before i wash with my NP?
In otherwords what PH?

After the wash i should base it to about 12-13, so the meth amine goes up to the NP layer, right?

Then I should add HCl to PH is about 6.5 to move the meth.HCl to the H2O layer..

and evap, right?

[gluecifer69]

After the wash i should base it to about 12-13, so the meth amine goes up to the NP layer, right?

Then I should add HCl to PH is about 6.5 to move the meth.HCl to the H2O layer..

and evap, right

Right, first base to at least 13, then pH to 6.0 and swim should have no problems.  Don't forget to recrystallize for final diamonds to rid any final nasties.

[kris_1108]

It may have been an idea to add a little more water at the end of your reaction, so you have more fluid to work with.
As for basifying it, you DONT need pH papers. Just add a NaOH solution, a bit at a time, and swirl. The pH will bee high enough when the fluid goes milky white, and does not clear up after a few minutes.
As for the excess HCl, if this ever happens again, just evaporate, and flash with cold, dry acetone. Wait for it to cool and then pour it off, leaving the meth. It will wash away the colour and the excess HCl. You may need to wash more than once.

[livid]

kris makes the most sense. keeping it simple. but before messing with the tone, see what you have, after you cook off the acid. could bee pure meth.

[jammin]

Thanks fore your advice, my friend will try this tonight!

Another thing though...
I always hear about evaporation should be done under low heat, but what temps are acually safe?

(What temps dosent evap or destroy the meth.hcl?)

[Newton]

I always hear about evaporation should be done under low heat, but what temps are acually safe

Any temp below the melting point will be fine. To be on the safe side, go a little above water boiling temperature, like 120°C. Or a bit more if xylene was involved in the last step.

[jammin]

but since the FSE is down what is the melting point of meth, around 160C if i recall right?

So a temp like 80C is considered safe?

[SHORTY]

171-174C

[jammin]

if i keep the temp below this no meth will avaporate?

What is the best temp to use and why?

[SHORTY]

I usually will heat to just below 100C. If it starts boiling then it can start popping out of the evap dish. You won't be able to evap it any higher than the bp of the solvent that you are evapping.  Besides it evaps pretty fast at 95C with a fan blowing across the top of the dish.

If your evapping in an oven then you would want the temp to be below the bp of the solvent you are evapping or you will end up with meth all over the walls of your oven.

[jammin]

But thanks to kris_1108's advice, im now a happy camper..

Goddamn, i never thought the acetone rinse would work so perfectly, thanks again!

(i bought a digital PHmeter to ensure this dosent happen again... But if it should, now i know what to do!)  

[kris_1108]

Hi jammin,
That's excellent news that the acetone rinse worked. I learnt that from reading

Post 428410

(geezmeister: "The post-reaction workup: a cook's summary", Stimulants)
I also learnt that you don't need a pH meter when titrating.
Heres some snippits
"WizardX gave some advice a long time back on this board to toss a few drops of HCl in water, toss it in the non-polar and shake well, then evaporate it. Keep evaporating each such pull by itself until you either get no more meth or the stuff you gets is so dirty its not worth messing with."
-------
"If you want the cream of batch, toss ten drops of acid in a 75 ml of dH2O and pour that into your non-polar solvent/meth solution in the separatory funnel. Shake like hell. Then shake some more, and when you are done, shake it again. Shake it like it meant something, because it does. Drain this out and evaporate it separately. Hey, so what if the pH is 8. You will already have some meth. Add another batch of water and acid, the pH falls more, you get more meth in the next pull. This is why most folks get the bigger yield on the second pull-- they have finally neutralized the mix."

So what you are doing is repeatively using a weak water/acid solution to 'pull' the meth out of the NP. Each time, the pH (of the water/acid/meth mixture) will be a bit lower. When it gets too low, you will see no more meth upon evaporation OR it will be soo dirty that its not worth eating.

[jammin]

Thats looked like a bright idea, but "ten drops of acid", it that conc hcl or the 30% stuff?

Swim only has 30%...

[embezzler]

anyway the h2o reaches saturation point at around 35% (afaik)
what you have is conc.

[Ganzas2003]

to do this:

add half in water of what u have in nonpolar.
since he reacted 2g of pfed he adds then 2ml of hcl lab grade 30%...

he shakes like hell. he waits like hell...25 minutes. he gets half of what he should be getting...he smokes it and he adds the same nonpolar back to the same reaction fluid. he lets it rest till next day.
he repeats and he gets the rest.

of course he washes 2 times with acetone to get white lovely stuff which burns completly.

from 2 gr he gets 1 to 1.3 of meth. not bad consederind he uses NO LABWARE.

cheers