5+kg methods

[Gale]

Is the all/hg suitable/preferred for large scale production? The more I learn the more I start considering exploring other routes such as the boro reduction is there any advantages for large scale? I've seen many labs using all/hg method have many small reactors instead of one large one. Is this because to reaction is more efficient at small scale?

I'm interested in researching large scale routes for something like 5-25kg, I assume the all/hg will work ok but is anything else more preferee and worth switching to?

Stirring is the main issue my stirrers couldn't handle 1kg al/hg reduction so o had to monitor it constantly.

As long as I have sufficient stirring and proper amalgamation then switching to 55gal drum with stirrer powered by compressor. If this will work ok and the drum gets up to temp that would be pretty nice but wouldn't be good to have it not fully react. Ever experience a stall? Sad stuff.

 

[KokosDreams]

It's said that the NaBH4/CuCL2 route will be more suitable for a 100L reactor. Also here I would recommend using multiple reactors instead of one big one.
It is confirmed that 2.5kg P2NP are easily suitable for a 100L reactor (confirmed by @btcboss2022). Maybe it would be possible to scale this further to 5Kg P2NP in a 200L reactor but I have no confirmation here

What big dutch labs do is using P2P instead of P2NP to synthesize freebase on the scales you are talking about.

Also, there is routes including hydrogenation tanks + catalysts that are more suitable for producing batches of the mentioned scale.
Unfortunately I have no further info on any hydrogenation routes.

 

[Gale]

I think u could even do like 4kg in a 100L reactor right? In a 19L reactor using 1.1kg pmk using Methylamine it almost overflowed with vigorous stirring I had to turn that off for a sec

Catalyct hydrogenation seems to be the way to go, I've looked into large scale lab busts and they all have hydrogen tanks and steel reactors. I think with hydrogenation you can be more sure everything has fully reacted I think. I like to be able to read a gauge that tells me when its done, which is why I like hydrogenation. I like no need for condensor.

Currently stuck with buckets mostly so hopefully I'll upgrade sometime. Stirring is a bit of a problem so I'm reducing reactions to 4x 800g then will upgrade in a few weeks

 

[KokosDreams]

Hmmm, you're right 4kg P2NP would mean a whole RM volume of approx. 60 liters.
That would probably be max as it could lead to a quite heavy exothermic reaction
Absolutely!! Did you found any publicly avaiable info that you could share?

I know that common catalysts are either Pd/c or PtO2. But I never found more info on these topics. Maybe the catalysts I listed will help you on your journey

 

[Gale]

The easily available online

The tricky decision is what you will use for pressure vessel, it gets pricey but I guess u have to spend money for a large reactor.. Soda syrup tanks for 1-2kg runs I think would work but too small for large-scale. I think there's a few options for tanks, I forget what psi the reaction generates but I think it was around 60psi

Example:

Using Platinum on Carbon (10%) Catalyst - by KrZ​

Reactants

• 4L MeOH containing 620g (20 mol) Methylamine
• 600g (10 mol) Glacial Acetic Acid
• 1600g MDP2P
• 100g 10% Pt/C

The GAA/MeOH/MeAm were combined and the MDP2P was added dropwise with stirring. When addition was complete 400g of anhydrous silica gel was added and overhead stirring was commenced for 6 hours. The silica gel was filtered off and 100g of 10% Pt/C was added to the mix. This was then placed in a hydrogenator and shaken for 4 hours, at which point 105% of the theoretical H2 had been absorbed. The mix was filtered once with vacuum to recover the catalyst (which was rinsed with MeOH), and again through celite to remove the brackish color present due to remaining catalyst particles. 4L of the solution was placed in a 5L distillation apparatus and 2L of MeOH was removed at atmospheric pressure, after cooling, the remainder of the mix was added, and distilled until the temperature rose to 80°C. After cooling, distillation was commenced again, collecting the acetic acid fraction. The residue was suspended in 5L water, basified with 25% aqueous NaOH, extracted with ether, the etheral solution dried over MgSO4, the ether distilled off under vacuum, and the residue was vacuum distilled, collecting 1400ml of MDMA. The MDMA was taken up in 2L of ether and saturated with HCl gas until crystalization had ceased. The total quantity of hydrochloride salt recovered was 1755g

 

[Gale]

This is a good tank, built in stirrer can buy buy them locally usually used

 

[KokosDreams]

My bad, I thought we are talking about amphetamine routes

 

[workworkwork]

1755g yield from 1600g MDP2P and almost no more chemicals needed!!! Best method ever, but impossible for me learn how to do this by myself. Maybe if there is detailed instructions or a video.

I will start with borohydride method, about 90% yield by mass and other chemicals needed not very expensive, 1.2kg methylamine HCL and 100g borohydride per kg MDP2P.

 

[Gale]

What is your method for borohydride reduction using methylamine HCl? I have a bit of STAB.

The catalyct hydrogenation actually is really simple as long as you can understand and learn how the vessel works, I don't thinkthe difficulty is that much higher than Al/hg it just comes down to getting a proper tank or modifying it and experimenting with some methods online and reading a few papers regarding hydrogenation for safety.

 

[workworkwork]

Maybe not difficult, Im starting, I was reading chemistry for dummies 1 month ago.

Is the the borohydride method from this thread

 

[Bartholomeus]

Nice post, where did you find this method If I can ask?
Are there any more large scale hydrogenation synthesis like this?
And I think the hydrogen gas has to be 'added'' more times during the reaction, or in other words the hydrogenation tank has to be charged with hydrogen gas few times during the reaction
Also It is quite dangerous when using hydrogen gas if you are not careful, I think first vacuum has to be pulled from reactor and then charge the reactor with hydrogen to be safe and not risking explosion
The big dutch labs are using this method all the time, It would be nice to see their synthesis method
And what concentration GAA should be used? 10mmol is what of concetration?

 

[Bartholomeus]

Okey found it, it is on Erowid

 

[UWe9o12jkied91d]

• 600g (10 mol) Glacial Acetic Acid.
  
  10 moles represents a measure of amount of substance, not concentration.The concentration this procedure describes is glacial, so pure

 

[Gale]

You will need to add hydrogen more than once but it will show you when to add more by reading pressure. Boro reduction seems good enough. Would a larger vessel be required for an Al/hg reaction vs hydrogenation synth?

 

[TotalSynthesis]

simply have a look for the biggest fire extinguisher you can find. It is a fantastic hydrogenation device.
and in terms of catalysts, if platinum is too expensive, have a look at raney nickel. i will post some results and procedures soon.

al/hg cant be scaled that much

 

[Gale]

Do you mean something similar to a fire extinguisher? I couldn't locate any giant fire extinguisher. You can use a paint pressure tank, search it up, some come with a pneumatic stirrer built in up to like 40L of Amazon. I think these are perfect, but like I said only 40L. You can find even larger ones locally depending on your location but paint pressure tanks look promising. Milk cooling storage tank, if that works then that would be suitable, anything that holds the required working pressure for the reaction. Just need to be creative. Any tank that will hold pressure and won't corrode and can add some kind of stirring unless you can rock vessel side to side. In that case use a horizontal standing pressure tank

 

[Gale]

Thanks,

Is there any reasons why it cannot be scaled? IME stirring a bunch of aluminium seems inefficient especially for a very large reaction... Al/hg is gross I haven't tried other ones but end up using like 12 liters xylene for 1kg I reuse to but, I don't have distillation equipment btw

 

[TotalSynthesis]

the biggest problem is the massive amount of exothermic heat is produced. the bigger the reaction the more difficult it will be to get it handled. It is like rocket fuel. With really big vessels and massive amount of external cooling, maybe even with dry ice, you might keep it under control a bit.

i did batches of 1-2 kg p2np via al/hg in what i call "the open system". Meaning i did not even try to condensate the vapors because the pressure would have just blown my coolers out, so i used the biggest reaction vessel i was able to find (300l plastic drum), in made a whole into the lid about 10cm x 10cm in size and focussed on constantly adding solvent at about the same rate it evaporates.

results have not been that bad, but the reaction is very nasty when trying to constantly feed this pousonous steam vulcano.

And the amount of used and lost solvent was massive

 

[Gale]

It
If the aluminium thickness is scaled as well, would the temps stay in control? I will explore other routes so should I commit to the boro reduction?

 

[Gale]

So you had no condenser eh , you can attach a vertical hose