Author Topic: Leukard scaleable ?  (Read 2857 times)

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6ULdv8

  • Guest
Leukard scaleable ?
« on: October 18, 2000, 03:45:00 PM »
Hey there people. SWIM has dreamed of using the Leukart process a few times now and is had success (40-50 % each time). This dream has been acording to that outlined in Vogels (using formamide, formic and mdp2p). The amounts aminated did not exceed 100g mdp2p. Could someone of the know, please let me know if this process can be scaled up indefinately without impacting on yields. Also if anyone has any tips on increasing the yield, I would love to hear them.
Thanks.

Antibody2

  • Guest
Re: Leukard scaleable ?
« Reply #1 on: October 18, 2000, 04:14:00 PM »
Look on the old boards for LabTop Huge Scale leukart. He was well into the kg quantities if I remember. With yields comparable to those you state.


Jimi loves ya

psyloxy

  • Guest
Re: Leukard scaleable ?
« Reply #2 on: October 18, 2000, 07:09:00 PM »

http://rhodium.lycaeum.org/chemistry/leuckart.txt:



"150 L MDP2P + 400 L NMF + 75 L Formic acid "

is that enough ??  ;)

--psyloxy--

6ULdv8

  • Guest
Re: Leukard scaleable ?
« Reply #3 on: October 19, 2000, 02:47:00 AM »
Thanks for the replys. I cant believe i didnt find those articles. I think 150l mdp2p might just be big enough  ;) .Has anyone actually had success using the microwave route , André Loupy et al, Tetr. Lett. 37(45), p 8177-80 (1996)? I would love to dream of this method, anyone got a 60w monomode microwave lying around that i can borrow ? hehe

Dope_Amine

  • Guest
Re: Leukard scaleable ?
« Reply #4 on: October 19, 2000, 08:49:00 AM »
The leukart is definately scale-able up to the multi kilo levels.  The key to high yields is having a much longer (1 week), gentler reaction.  Or, so I hear from the Europeans..


something for your mind.......

6ULdv8

  • Guest
Re: Leukard scaleable ?
« Reply #5 on: October 19, 2000, 10:21:00 AM »
Dope_Amine..thanks heaps for the tip. I am going to dream up some more mdp2p this weekend then i will run a few leuckarts of varying sizes with increased reaction times. I will post the results. :)

psyloxy

  • Guest
Re: Leukard scaleable ?
« Reply #6 on: October 20, 2000, 01:51:00 AM »
This is something you might be intrested, a variation of the Leuckart, that doesn't even use formic acid and has yields reported as high as 70%

"The setup used is the same as in fig. 12(remember no vacuum!). and into the rxn flask is placed 275ml formamide, 80g MDP2P and 55ml of 9% glacial acetic acid (50ml dH2O + 5ml GAA) This is slowly heated to 140-150°C in the oil bath and kept there for 5 hours. The lower the temperature at which a sustained reaction (bubbling) can occur the better. Suffice to say that 150°C should not be passed. Very early on the water and AcOH will have distilled over and can be discarded.

After 5 hours the reaction is stopped and the flask cooled. The formyl-MDA can be isolated and hydrolized by any of the ways Strike just mentioned a few paragraphs back, but this method offers a third, very convenient way which should be tried. What the chemist does is forget about letting the flask and its contents cool. Instead, she removes the oil bath, places the flask back on the stirplate (distillation setup still attached), attaches  a vacuum and distills off all the formamide. What remains is a dark, heavy formyl-MDA precipitate that is allowed to cool down while the chemist makes up a solution of 150g KOH, 500ml EtOH and 125ml dH2O. This solution is poured into the formyl-MDA residue, the condenser from the distillation set is plopped in vertically and the solution refluxed for a mere 30 minutes. The solution is then acidified with concentrated HCl solution, the distillation setup reattached and all the ethanol distilled off under vacuum. What is left is MDA and aquaeous HCl and from this the MDA is liberated, as usual, by basifying with NaOH, extracting with solvent, drying the solvent and distilling to get MDA in 70% yield."

figure 12 shows just a simple distillation setup in an oilbath on a stir/hotplate.

--psyloxy-- Yeah mdma is funny but has anyone ever experienced ayahuasca ?

6ULdv8

  • Guest
Re: Leukard scaleable ?
« Reply #7 on: October 20, 2000, 03:32:00 AM »
psyloxy: wow thanks ! this method sounds great (never thought one could get anywhere near 70% yield with leukart).If this variation works out and is scale-able, i will be a real happy camper  :) The leukart is so much easier than many of the other methods, i dont know why more people dont use it.

psyloxy

  • Guest
Re: Leukard scaleable ?
« Reply #8 on: October 20, 2000, 12:29:00 PM »
At the beginning the Leuckart rxn produced mainly tar and maybe 20% goodies, that's why the older bees don't like/perform it. BTW if I had access to NaBH4 I,too, wouldn't bother with it.

--psyloxy-- Yeah mdma is funny but has anyone of you ever experienced ayahuasca ?


Antibody2

  • Guest
Re: Leukard scaleable ?
« Reply #9 on: October 25, 2000, 09:15:00 PM »
Dope amine - that makes some sense, RC claimed a 36g product from 40g ketone using leukart w/ formic and formamide. and he let it go alot longer than 7 hours, 29 hours methinks.

What exactly did you hear regarding "gentler reactions", be curious to know how much gentler.

RC also mentioned maintaining PH at 4.5. Wonder what reference that came from? Anybee know?


Jimi loves ya

Dope_Amine

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Re: Leukard scaleable ?
« Reply #10 on: October 27, 2000, 05:15:00 AM »
Sorry, I didn't notice your reply 'till now.  I don't know about the pH thingy. Best reaction temp.= 135-140 (barely bubbling) for 3 dayz. Good luck.


something for your mind.......

LaBTop

  • Guest
Re: Leukard scaleable ?
« Reply #11 on: October 27, 2000, 09:12:00 AM »
Yep, highest temp would be 160 C, not the 190 C mentioned in my thread, there must have been something wrong with that digital thermometer those times. Medium bubbling will be seen at that temp. LT/


WISDOMwillWIN

Antibody2

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Re: Leukard scaleable ?
« Reply #12 on: October 27, 2000, 03:29:00 PM »
3 days, no kidding, what kind of yields are being realized tbhis way? What do you think LabTop? About this route compared to NaBH4 if an amphetamine is what is desired NOT a methamphetamine.

Yeilds seem about the same.


Jimi loves ya

Vibrating_Lights

  • Guest
Re: Leukard scaleable ?
« Reply #13 on: January 17, 2002, 09:27:00 PM »
Could the formamide be replaced with acetiamide for the same results.  Or is formic liberated when the amide condenses with the ketone reducing O which i am assuminng that acetic will not. But then again why fuc karound withthat when hydroxlamine will do the same trick in al/Hg.
vL_

terbium

  • Guest
Re: Leukard scaleable ?
« Reply #14 on: January 18, 2002, 04:19:00 AM »
Could the formamide be replaced with acetiamide for the same results.
No. The formic acid moeity is specifically required since it is the reducing agent in the reaction.