1-Phenyl-2-propanone (P2P) Leuckart amination to amphetamine and methamphetamine. Smale scale.

[Hank Schrader]

I will share the table with you.

 

[OrgUnikum]

Maybe it is just fair to add that temperatures over 180 °C like the named 200 and 210 °C for sure completely destroy P2P and even the Formamide, the resulting vapors and gases are highly toxic. Vent everything coming from top of the condenser outsides! Seriously!
Keep it below 180, better below 175°C and calibrate the Infrared thermometer to the flask/setting you use or you will never exactly know how hot it is.

Good luck

 

[ZACARIASKLK123]

But how many minutes, 30 minutes like it states or 10 minutes divided in three portions at 60w? 150 - 160C?

• 15minutes total?, because I have read some did that.

I want to try this synthesis, since I have a colleague who happens to have a microwave reactor

@G.Patton @William Dampier Any input on this?

• Or perhaps The end of the reaction is determined when the gases cease to be released?

 

[OrgUnikum]

I attach the article and you can look for yourself. I saw a post elsewhere where somebody claims good yields like 80% in a modified household microwave(hole for condenser) with temperatures not over 175°C to avoid Formamide decomposition. No further details were given on this.

 

[Hank Schrader]

We love the purity of the product.
I have tried many ways to synthesize dextromethamphetamine.
Leuckart, amalgam, electrolysis method, reactor, boron hydride.
A method for obtaining methamphetamine from synthesized ephedrine was also tested.
Ephedrine was obtained in various ways.
For my consumers, I have found the best product with high activity and crystal purity.
The cost of obtaining 1kg of dextromethamphetamine is only ~220-250 euros

 

[googie]

Does the ephedrine synthesis perhaps involve α-methylamino-propiophenone hydrochloride & nabh4?

 

[OrgUnikum]

How much N-Iso was needed to have the racemic Meth form those nice crystals?

 

[BamBam]

7. Crude methamphetamine free base is distilled under vacuum (2 mbar, 60-100 °C) with help of Kugelrohr distillation apparatus (optional) to yield methamphetamine as a clear to pale yellow oil (2.5 g, 42%).

What’s other option? Simple, fractional or steam distillation? If don’t have Kugelrohr distillation apparatus?

 

[UWe9o12jkied91d]

Your mixture has easily separable components with very large range of bp's, so fractional is out.
Your product degrades before reaching bp, even more so than the primary amine derivative, so normal distill out too.
Steam is the way to go, preferably from an alkaline solution of 35% NaOH at most to prevent alkaline hydrolysis.

If by any means you prefer this you can also just perform a solvent extraction from basic sol. using something like toluene, strip off the organic layer and acidfiy to ph 2-3 followed by water. Next this added water is separated and organic fraction is discarded.Kept aq layer basified and rextracted with clean solvent.

 

[BamBam]

Thanks mate, much appreciated

 

[rothschild33]

What is the function of the NaOH in steam distillation?

 

[rothschild33]

What is the function of the NaOH in steam distillation?

 

[BamBam]

Do you mind giving me a little more info on prevent alkaline hydrolysis.
As I’ve done the reaction and now have produced as a dark oil in toluene.
can I just steam distill by adding water to Rm or better to add aq Noah solution?

 

[Win Win]

Hi sir if i want to follow your ingredient. Is it i need start bmk turn to p2p first. Then p2p turn to amphetamine? Last amphetamine turn to methamphetamine?

 

[googie]

Why amphetamine -> methamphetamine?

You can go straight to meth with the P2P.

 

[masterpell]

Can Benzene be replaced by other materials? Can anhydrous acetone be replaced by ipa

 

[G.Patton]

Hello, yes. You can use DCM, ether, toluene or xylene instead of benzene. And yes, acetone can be replaced by IPA.

 

[btcboss2022]

Recently I started to alternate Leuckart route and NaBH4 route for D-Meth and
I had twice a strange situation in the Leuckart route.
After tartaric isomer separation when I turns the solid part alkali to remake separation the freebase goes to the bottom layer.
It only happened with the L-meth freebase from Leuckart route, before separation when its racemic in alkali ambient is top layer, the líquid part after isomer separation(D-meth freebase) when its alkali is top layer too as it should be but Lmeth freebase no.
Is strange and I dont have the explanation I dont know if someone has the same situation or know why this happens.
Thanks.

 

[btcboss2022]

Ok I made an acid-base washing and in the acid phase appeared a fucking impurity not soluble in the solvent as the rest of impurities and not remain in the water with the freebase just goes to the bottom.
Possibly I made a mistake during Leuckart procesos many things at the same time hahah
The mistery now is why only appears after isomer separation and only in the Lmeth side because I made the same washing for Dmeth freebase and it didnt appeared, seems curious at least
Pic is from the ácid phase solvent top layer water with freebase médium layer and unknown sticky impurity in the bottom layer.

 

[w2x3f5]

Even the color in the first photo says that you have dirty oil with a significant impurity, did you distill the amine after Leuckart-Wallach? Leuckart is known to give a mixture of various secondary/tertiary amines, possibly some other impurities. Hank Schrader posted an excerpt from the study, in which the formation of impurities in the Leuckart-Wallach reaction is considered in more detail.
Also, the separation of isomers could not have been satisfactory due to the low purity of the free base of the amine.

 

[btcboss2022]

Thanks for your answer.
I always wash and clean the freebase after isomer separation no matter what route I use.
Is just an economical matter at big scale.
You dont use the same amount of reagents to clean the whole racemic freebase than only the separated part.
I dont know where you see the freebase in the pic, if you read it carefully you will see that is not possible to see it due its in the water layer.
About the separation of the "dirty" freebase(its extracted and dried) I can tell you that its works properly the proof is the final stuff obtained(pic added) and also I get less D freebase each time I remake the process to the L freebase so it works its a fact.
I isolated that"impurity" and it gets dissolved in DCM but not in Hexane and now its a dilemma I dont know if Hexane is not enough good solvent for that kind of products or if DCM dissolve some organic impurities :-(
Thanks

 

[btcboss2022]

I forgot the pic sorry.

 

[btcboss2022]

I forgot the pic sorry.

 

[w2x3f5]

The question was: did you purify the free base of the amine before separating the isomers? Leuckart impurities are secondary/tertiary amines and can only be removed by distillation of the free base of the amine.
The question was: did you purify the free base of the amine before separating the isomers? Leuckart impurities are secondary/tertiary amines and can only be removed by distillation of the free base of the amine. I asked you how you purified the free base before isomerization, not after isomerization.
With distilled oil, I have never had problems separating isomers, and it does not matter if it is p2p meth or amp, or p2np amp.
When isolating the salt of the L-isomer of d-tartaric acid (distillation of alcohol), I was left with a dense, sticky oil of a slightly yellowish color.

 

[w2x3f5]

the crystal can also be obtained from mix D and L isomers meth, I personally did it. You did not measure the angle of rotation.

 

[w2x3f5]

I can send you in private messages a photo of glass obtained from dirty amine oil. I studied the possibility of obtaining large pieces of glass without vacuum distillation, also there was no separation into isomers.

 

[btcboss2022]

I know how pure meth freebase looks like I used to do steam distillation and did vacuum too you must think that freebase of the pic still needs to be extracted and dried but as I explained I'm able to obtain the exactly same pure and strong final product from this freebase, avoiding distillations, than from the distilled one, you won't distinguish them in fact nobody told me anything about any difference in the product and I changed the process long time ago without saying and lab reports indicate exactly the same purity %
Happy to receive the pics thanks.