how long for Al reduction in Os MeAm Al/Hg

[RoundBottom]

roughly how long should the aluminum reduction take in a ~100g scale Osmium MeAm Al/Hg? 

after the initial reaction with HgCl2 and then the MeAm/NaOH mixture, the reaction slowed way down.  the Al doesn't seem to have gotten much smaller (but it's probably thinner) after about 12h of stirring.  the solution is now dark grey and cloudy, so there has been some reduction.  it's not sludgy like a MM Nitro, but a little darker and more watery.

4x 25mL 40% NaOH have been added along the way, but that hsan't had much of an effect.

here are the reagent amounts used; the Aluminum is an 0.01mm/.004" thick oven liner chopped up to 1cm bits, and the ketone from a buffered performic and is suspected to be 75% (could do with a redistillation, i know) but it does yield when used in a MM Nitromethane AlHg.  the MeAm.HCl is from chromic's unpublished procedure.

MDP2P 122g (suspected 91g ketone)
Al    36g
MeOH  600mL
HgCl2 230mg

dH20  169g
NaOH  53g
MeAm  90g

the NaOH and dH20 were mixed and allowed to cool.  the MeAm.HCl was mixed in, and the NaCl was allowed to settle.

560mL MeOH was put in 3L 3N FB flask with 3" octagonal stir bar.  the HgCl2 was added and disolved, then the Al was then added.  after that started amalgamating for 45min, the MeAm/NaOH sol'n was added and allowed to mix.  the ketone and 40mL of MeOH was put in an addition funnel and started a quick drip.  after 25min the additon was complete and heat was added.

25mL of 40% NaOH solution was added at the 235m, 435m, 610m, and 720m marks.

the mixture will be left to stir overnight.
i learned a thing or two from charlie dontcha know.

[abacus]

RB, SWIM recently tried a similar reaction (Using 1 Mole Ketone)with thicker AL (0.3mm soft alumnium flashing).  Added the meam and enough 25% NaOH to nuetralise the meam (via chromic method) and found the salt covered the aluminium sitting on the bottom of the flask. Heated to reflux for 2 hours and still NOTHING was happening.

SWIM was panicking as NOTHING was happening and the aluminium was still sitting there doing fuck all!!!

So, in desperation, the mix was decanted into a buchner funnel, leaving the unreacted aluminium in the flask, and the methanol sludge was filtered.  The left over aluminium was rinsed with more methanol which was added to the buchner, and then the left over aluminium sitting in the flask was then covered in a little methanol to stop it oxidising,

So the sludge was filtered and the filterate set aside. 

Then a few mls of nitro was added to the now clean aluminium sitting in the flask to test its reactivity, and  KABOOM, instant reaction and all the methanol boiled out of the flask. 

Now that SWIM was assured the aluminium was fine and really REACTIVE, the methanol filterate was added back to the flask and KABOOM 2 !!!!!!!!!!!!!!, instant reaction and reflux that ran as fast as a hot nitro reaction.

SWIM couldn't believe it, it refluxed for over an hour until it slowed.   Left to react on its own and cool overnight.

Next day extracted and yielded over 150g oil which was then distilled and gassed (following acid base wash). 

Best ever yield for swim.
Hope this helps
Abacus

[Osmium]

> RB, swim tried a similar reaction (Using 1 Mole Ketone)
> with thicker AL and found the salt covered the aluminium
> sitting on the bottom of the flask and after a few hours
> NOTHING was happening.

That's why you need GOOD stirring!

Just let that thing run for a full day, if there's still unreacted Al left it won't matter. Reaction speed depends on many factors, including stirring, temp, and most importantly Al thickness.

I'm not fat just horizontally disproportionate.

[RoundBottom]

well, that sucker is spinning away, and there might be some scratching of the flask, as i can hear the Al scrapping along.

i think adding the nitro defeats the purpose of using MeAm.  if it goes KABOOM! do you not run the risk of making tar that will trap product? 

Os, you say that unreacted Al after 24h stirring is not a big problem?  is there any advantage or disadvantage to letting it go longer?  are there any signs to look for that indicate completion?


there was supposed to be a big kaboom.  where's the kaboom?
                    marvin the martian

i learned a thing or two from charlie dontcha know.

[abacus]

RB

What I meant was nothing was happening when SWIM tried it  and addding a couple mls (ie no more than 5 mls) of nitro after decanting and washing the aluminium, somehow caused SWIM's aluminium to be more reactive.

When the methanol containing the ketone and methylamine (about 170 grams now dissolved in the methanol) was then added back to the flask containing the slightly reacted (now greyish) aluminium, an immediate reaction started that was as fast as a nitro reaction and over in the following 2 hours.  Ended up reacting 1 mole ketone in a 2L flask in a few hours, then left overnight with no stirring. 

SWIM can't explain it, maybe it was crap aluminium to start with and all the nitro did was help amalgamation, who knows.

[RoundBottom]

the last time an Os of the same size was tried, it wouldn't stir because the Al was cut in 1" squares, so it was swirrled whenever possible.  the liquid was decanted, leaving the unreacted Al (a lot was still solid), Al sludge and some liquid in the reaction flask.  1.5L 35% NaOH was added slowly to the solids and sludge.  within 30 seconds, gas was jetting out the 3 necks as the remaining Al was reduced in a matter of 1 minute. 

the flask was already sitting in a sink, so it was filled with cold water and ice dumped in to slow the reaction.  unknown if this helped, or the reaction just pettered out.  it was almost like one of those fireworks that shoot sparks up like a volcano.  there was no solid Al foil left in the flask, and there was a scummy dark brown/red, viscous liquid floating on top, almost like pond scum.

the problem with this rapid reduction was subsequent toluene extractions were a burgandy colour, like wine.  subsequent gassing produced orange pulp like solids.  possibly product tied up in tar.  no cleanup of product was tried.  cleanup of aparatus was a bitch.


i learned a thing or two from charlie dontcha know.

[Rhodium]

You forgot to perform an acid/base extraction of the product, as well as vacuum distilling the freebase afterwards. That's why you got no crystals.

[RoundBottom]

from that point (the basicification) the ritter/MM cleanup was followed.  basify, mix with toluene, wash (3x dH2O, 1x sat NaCl), dry, gas. 

none of the washings helped to clear the toluene.  it remained transparent reddy/brown, like cool-aid of a wierd flavour.

this was the first time an Al/Hg "failed".  ideally, the freebase should have been cleaned at that point with an Acid - Base cleanup, but SWIM didn't know better. 

now, SWIM is in the same spot.  there is unreacted Al in the sludge, so the sludge will be extracted with fresh MeOH before acid - basification.  SWIM has only done the ritter cleanup, never an A/B, so thie will be another learning experience.

i learned a thing or two from charlie dontcha know.

[Rhodium]

I really must edit the MethylMan Al/Hg document - the skipping of the A/B extraction at the end is causing SO many troubles for bees, and probably an accumulated amounth of several kilos impure MDMA.

[RoundBottom]

so the ritter workup is not acceptable for any kind of final product quality?  that's a shame.  did we ever find a final BP of MDMA freebase in the merek?  this is important info for final distillation of the freebase.  i would think that rotavaps are less of a luxury now, too.

maybe we should moderate some edits for all the common workups.  vote on changes or something.  or just modify them and don't consult anyone (but please make the updates evident in the writeup, with revision notes or something).

thanks Osmium, Rhodium, and Abacus for your input.

i learned a thing or two from charlie dontcha know.

[Rhodium]

Here is a proper A/B workup with crystallization, as well as a proper freebase vavuum distillation of MDMA with boiling points:

http://www.erowid.org/library/books_online/pihkal/pihkal109.shtml

[abacus]

Rhodium, you have a damn good idea.  BTW edit all the other misinfo that is still on your archive. 

Some of the methods eg MM's is crude and ALL bees that DON'T do the acid base wash and then distill the freebase really don't know what the hell they are doing. Such posts only promote such crap procedures.

Once you try distilled freebase product, you wont go back to the crap!!!!!

[Rhodium]

Could you do me a favor? Could you go through the MDA/MDMA/MDE methods at my page and check which ones doesn't use a proper workup, so that I can correct them (PM me the list). I have limited time, so if you could to that part for me I would be very grateful.