Modifications to MM's Al/Hg Nitro

[goiterjoe]

OK, I know there are plenty of you out there using methyl man's Al/Hg nitro reduction, and was wondering how many of you have modified it.  I found it necessary to make certain modifications to get it to work properly.

The first couple of times I ran the reaction, I mixed the nitromethane and the MDP2P together in the addition funnel and added them together.  This kept resulting in a waxy byproduct that acidified out in the end with the MDMA.  My assumption is that this product was a result of the nitro reacting with the ketone under high temperatures.  To fix this, I simply added the nitro first, waited for the reflux to calm down, and then add the ketone.  This brought the yeilds up to where they were supposed to be. 

The next part of the reaction I modified was the extraction and subsequent workup.  Instead of basifying the whole mess, I started filtering out the aluminum sludge, then washing the aluminum twice with more methanol, pooling the mother liquid and the washes, and basifying this.  This has dramatically improved workup time by not having to wait for the remaining aluminum to be eaten away and then having to deal with that large mess.  The NP gets cleaner with fewer washes, and the NP separates out much faster after shaking in the separatory funnel.  I also like this because the mercury content of the methanol you are working with is not as high as it would be had you left the aluminum in the reaction.

[SPISSHAK]

Good work, can we have full details of the expirimental?

[Chromic]

I totally agree with the modification of adding the nitro first... good work. Interesting idea on the work up.

[goiterjoe]

The basis for the workup comes straight from PIHKAL #109.  OK, not directly, because I didn't do a vacuum fractional distillation.  Anyway, the aluminum always makes the final extraction a bear, and the mother liquor is extremely thick from all the alumimun trash.  Filtering makes the liquids a lot easier to deal with, because basically all that is left is some pretty clean methanol containing your freebase.  The mass can take a while to filter, so it helps to try to leave as much of the aluminum sludge still in the flask.  You can do your washes inside the flask, and on the last wash you dump the aluminum leftovers into a clean filter paper and wring them out. 

Another nice thing about this is that you have a solid waste to dispose of instead of a huge bottle of liquid waste.  I'm pretty skeptic about flushing solutions containing mercury, and I'd much rather save the waste to bury later.

[RoundBottom]

i completely second mr max's observations.  leftover Al usually means impure ketone... something SWIM has become intimately familiar with as of late. 

and straining out the foil is the way to go... just rinse it with ~50mL MeOH while it is in the tea strainer (the tea strainer that is over the funnel that is over the separatory funnel.)

this suggestion of adding all the MeNO2 before the ketone... this is a good idea?  or is it better to add just a bit, ~5mL, at the begining after amalgamation starts but before addition?
i learned a thing or two from charlie dontcha know.

[goiterjoe]

I'm talking about that leftover aluminum sludge that sits at the bottom of the flask.  Filter that out.  If you've ever added excess aluminum to a reaction, you will have aluminum left over in the end.  Big deal.  If you  can get back almost gram for gram what you put in, you're not losing anything.

[baalchemist]

"Instead of basifying the whole mess, I started filtering out the aluminum sludge, then washing the aluminum twice with more methanol, pooling the mother liquid and the washes, and basifying this.
This has dramatically improved workup time by not having to wait for the remaining aluminum to be eaten away and then having to deal with that large mess."

Baal has never found filtering large amounts of sludge saturated reactants prior to basification any easier nor faster. In actually its much slower that way and requires much more time & labor overall and usually an A/B. After basififying a reaction mix, the Al. sludge volume is reduced next to nothing by comparison, the non-polar quickly & easily sucks the goods right up out of there. If it takes more than 30 mins. for the sludge to break down, either there was too much Al., reaction was'nt run to completion, or not enough base was added. Heating will speed up that process nicely, or adding a little extra NaOH can help it along.   

 "I also like this because the mercury content of the methanol you are working with is not as high as it would be had you left the aluminum in the reaction."

Water in the reaction/rinse MeOH will help carry HgCl2 right along with it anyhow if its not reacting with anything, nothings gained but a few mg's less of potential exposure. All HgCl2 is removed anyhow with the saturated brine wash of the non-polar extractants.

This reaction when run correctly, will result in a clear non-polar layer that doesnt require any extrordinary efforts to wash, 1 brine & a couple of h2o washes is it.
Baal will dump his post reaction mix into a bucket & with stirring add toluene & then NaOH. After 30 mins toluene layer removed, then another volume of toluene is stirred for 15 mins & removed. Into a sep. for the wash, then dried and gassed. ~3 hours reaction time,~2 hours max final workup time here. Nonetheless, if its workin better for you that way, awesome! Keep in mind, a little patience goes a long way in chemistry, taking the long way home is best left for those still learning the way. You'll be a pro soon enough, best 'o luck to ya!!!!!    


 
    GODISNOWHERE
Shoot Narcs, Not Drugs

[Chromic]

1) Most of the mercury will stay amalgamated with the foil. No worries.

2) Washing your non-polar with water is a no-no. Read Dope_Amine's post on the matter.

3) Consider filtering your non-polar early in the game. Wash once (with something like 5-10% NaOH), suction filter it, wash again (5-10% NaOH), then with brine. Dry with MgSO4, filter again, gas. I think it's a much easier way to look at doing things anyways.

[SPISSHAK]

SWIM posed a question about this earlier, If one were to use mercuric iodide as opposed to mercuric chloride; would using brine to wash this out solvate the mercuric iodide as effectively as it would the chloride?
SWIM cannot seem to find solubility data for mercuric iodide in salt water.
He has found data for Mercuric Iodide in solutions of NaI and water though, and it is an analogous principle of ion pairing increasing solubility of mercuric ions.

[goiterjoe]

I've don'e it MM's way a few times, and personally I think this works a lot better.  The filtering only takes about 10 minutes, and the mercury will stay with the aluminum.  The time saver is that the NP extraction can be done almost immediately after the caustic soda is added.  Takes about 2 minutes for the NP layer to separate out, and I used to give the second NP extract around 5 minutes to separate out competely.  No bubbles of aluminum soaked water getting stuck around the separation line or coating the sides of my sep funnel.  It really makes cleanup a whole lot faster.  Unfortunately I don't have a ring stand, so I like not having to hold my sep funnel upright any longer than necessary.

As far as washing goes, if you're not washing with a saturated bicarbonate solution, then you're just playing with it.  The bicarbonate wash is supposed to break down any remaining mercury salts and make them extremely soluble in the water/methanol.  IMHO brine washes don't do that much either.

Patience is a virtue of mine though, because I acidify my crystals out instead of gassing.  One of the greatest pleasures I got out of cooking was seeing the sheet of crystals appear in a pyrex dish.  It's cool having chunks of MDMA that you can see through.  It's totally different than meth, and it my opinion a much prettier crystaline structure.

[terbium]

You shouldn't have any mercury salts post reaction that need washing out. All of the (very small amount of) mercury salts that you added should have long ago reacted with the aluminum to form metallic mercury.

[abacus]

Some comments from experience

Firstly

SWIM has found that adding the nitro first, letting it react for a while and then adding the ketone has improved yields considerably.

Secondly

You don't have to wait for all the post reaction excess al to break down fully, just basify with NaOH and when the layers have good seperation, first decant the bottom sludge layer and then decant the non polar into another container, leaving all the unreacted aluminium in the seperating funnel.

Thirdly

Why dont you guys do and acid base wash and then distill your freebase?

Abacus

[GOD]

The first couple of times I ran the reaction, I mixed the nitromethane and the MDP2P together in the addition funnel and added them together. This kept resulting in a waxy byproduct that acidified out in the end with the MDMA. My assumption is that this product was a result of the nitro reacting with the ketone under high temperatures. To fix this, I simply added the nitro first, waited for the reflux to calm down, and then add the ketone. This brought the yeilds up to where they were supposed to be.

Is this why swiy adds an excess of Al?
Could you give an aproximate % of how much extra Al is added.  Also, when adding the nitro first, is it safe to pour the nitro in, or does it need to bee dripped in?
Any other points regarding this procedure would bee appreciated.
DMT... its good for what ails ya!
Just remember to bring back some of the love.

[terbium]

Also, when adding the nitro first, is it safe to pour the nitro in, or does it need to bee dripped in?
Don't pour the nitromethane in. The reaction of nitromethane with Al/Hg is strongly exothermic (produces a lot of heat). If you just add all of the nitromethane at once everything is going to boil out of the flask.

[abacus]

Terbium, it depends on the thickness of the al and how much nitro you add at once. eg

SWIMS experiments indicate the easiest and best yielding procedure for that be was:

Using aluminium flashing that is 0.3mm thick and carrying out a 100g ketone nitro al/hg reaction in a 3L flask.  

70ml nitro is added AT ONCE to the al and hgcl in 2L methanol.  The reaction heats up and boils very vigourously but a good condenser cools it quite well without any volcano.

Thirty minutes later the remaining nitro and 100g ketone is dripped in over the next 30 minutes.   THis seems to produce a very good reflux rate which results in heaps of turbulence in the flask minimizing the need for stirring IMHO. 

SWIM gave up stirring long ago with only small drops in yield. 

Then allowed to sit overnight.

NB:  THe key was also getting a good brand of flashing as more experiments proved that the yield could go from 0 to 60-70% depending on the brand of aluminuim.

 

[lab_bitch]

abacus:  how much HgCl2 and aluminum do you use?

[RedMonn_16]

I didn't know Joe Walden made drugs!

[abacus]

lab bitch

105g Aluminium and 0.5g HgCL

Howvever, I must point out that although SWIM has had many successful reactions in the past, lately SWIM has had many failures and doesn't fully understand why.

Many experiments were carried out using Al203 and Al(OH)3 as the model and various amounts of water which ultimately led to wasted time and effort so instead of trying to repeat previous successes, SWIM has now switched to making methylamine laden methanol first, and then carrying out the al/hg with ketone.

Now, failures are a distant memory.

Abacus
The problem is what you don't know you don't know.