Methamphetamine Synthesis. Leuckart Method From P2P.

[CryoThio]

The leuckart is so simple, but the yields are absolutely garbage.

If people could figure out how to increase yields, this would help the clandestine chemistry community so much.

Apparently magnesium chloride can be used as a catalyst, from what I've gathered online, maybe that will help yields a few percent points.

 

[jackofspades]

I don't have the link on hand, but I have read amongst the Rhodium archives that the use of a Dean Stark trap filled with water increased yeild. By removing water as it was generated but keeping the trap full gave a bette result.

 

[41Dxflatline]

A Brief Review: Advancement in the Synthesis of Amine through the Leuckart Reactionby Qasim Umar and Mei Luo

A Brief Review: Advancement in the Synthesis of Amine through the Leuckart Reaction

This review presents a summary of reactions that take place during the “Leuckart-type reaction”. The significance of, as well as recent advancements in, the synthesis of amines through simple and inexpensive methods using readily available raw materials is discussed. This review includes all...

www.mdpi.com

There you go, massive increases in yield and also speed.

 

[The_Real_Gus_Fring]

I don't understand any of the shit in that paper, please break it down. Also how high is the yield with this, what chemicals need to be used and how fast does this speed shit up? If possible just make a diagram plz.

 

[Fernandohatescorn]

Ok how much yeild increase is it and is there any synthesis of this done with ratios of Chems

 

[Win Win]

What is the ratio?

 

[Jesse_Pinkman_]

Did you read the beginning of this thread? Please do it carefully, everything is written there.

 

[situ1984]

Thank you, this is very useful to me. Can you help me make another detailed process for hydroiodic acid and ephedrine? I want to start simple.

 

[rothschild33]

Will formic acid speed up the reaction?

 

[OrgUnikum]

Not really. But it will improve yields quite a lot. Hydrolysis with 15% HCl and Methanol as co-solvent at 115 °C improves yields significantly. You need a vessel able to withstand 5 bar pressure for this. Rapid heating to 115 °C - 15 minutes - rapid cooling to rt.

 

[Researcherr]

What about using Naoh + methanol for hydrolisis?
And why do you say if using hcl+methanol it needs rapid cooling?
Which ratios do you propose to use if adding formic acid to reaction?
1 p2p : 2.5 NMF : 0.7 formic?

 

[OrgUnikum]

Methamphetamine hydrolyzes too, back to P2P actually. So if you run the hydrolysis to long and/or with too hard conditions you destroy the meth itself. With methanol you need a pressure vessel but its quick and complete. NaOH can be used too, no big difference, yields are higher with HCl though.
The Meth hydrolysis is reduced by rapid heating/cooling.
It is pretty brutal conditions the poor molecule is subjected to in any case, you should be aware of this.

A good quality stainless steel (316 or better) passivated with hot 75% phosphoric acid will have no problem with 15% HCl*. NaOH is no problem for any steel thats the advantage.
*regular inspection is advised neverthelss, in special at the seams and weldings, knock with a small hammer and listen, when the sound is not ringing but dull this points at corrosion. Like "doing, doing, doing, dudd, doing..." The "dudd" tells there is a problem.

The more NMF the better, the formic should be 85% strength or one has to add some water. This is also best done under pressure, 165 °C - 180 °C and then it is a also a very fast reaction.

Interestingly it was found that the quality of the NMF has a big influence on the result (yield), the difference was up to 25% depending on the manufacturer (and that was with high-regarded brands like Fluka, Fisher and MERCK). The water content might be decisive here. As water is needed, distilling all water off ruins everything.

A pressurized vessel is the way to go as with any reflux setup one runs into the problem that water/P2P will distill off into the condeser and not ever return to the reaction as it immediately goes into vapor phase again when hitting the much hotter reaction broth. This has the reaction starved on water and P2P despite nominally being in optimal range.

 

[Researcherr]

@GhostChemist
why do 2 hydrolisis? first naoh hydrolisis and then hcl hydrolisis?
isn't one hydrolisis with naoh+methanol enough?

 

[Vinayak]

i m trouble
Plz help me any one
results it’s done
But it’s gets powder how to change the glass cryistals format
Plz help me
I m begging

 

[lalosalamanca84]

hi...maybe somebody know i have 50 L jacket reactor...and heater and coller device i no know how to conect propertly...i make like this

this is my machine...i follow the manual but i conect all and level of oil no go to all jacket space only go 1/4 , oil in pump inside but oil out is more fast...no can make balance to jacket be full ...

this is photo in (up) and out (down)

this is IN pipe...on up on reactor...

this is out pipe ( where oil suck up and go back in coller / heater machine )

this is level oil what go inside and no go more up...pipe ho suck is more faster...somebody have solution or some advice...tnx