The Vespiary

The Hive => Newbee Forum => Topic started by: pink_dust_angel on August 24, 2004, 05:24:00 PM

Title: leuckart question
Post by: pink_dust_angel on August 24, 2004, 05:24:00 PM

in a leuckart wallach reaction can formamide be used alone or do you still need formic acid as well.
im just a little confused as people seem to be using formamide alone but i dont see how this can be used as a hydrogen doner for reduction.

Title: in a leuckart wallach reaction can formamide...
Post by: DoctorFeelgood on August 24, 2004, 09:26:00 PM

in a leuckart wallach reaction can formamide be used alone or do you still need formic acid as well.

if you can obtain pure formamide, you can use it just like it is. i use formic acid together with ammonium hydroxide to MAKE formamide. therefore you have to add ammoniumhydroxide to formic acid, until it is neutralized. then you have to heat it, to get formamide. use TFSE for further info on this topic, you should find a lot of posts.

im just a little confused as people seem to be using formamide alone but i dont see how this can be used as a hydrogen doner for reduction.

make some ammonium formate by heating the neutralized formic acid in a standard distillation setup and discard everything up to about 160 C. you should be left with a mix of ammonium formate and formamide, which i used with good results in leuckart reactions to make some mda. again use TFSE.

Added 46g MDP2P to 130g formamide (homemade) and placed in a flask sitting in an oil bath with glassware setup for normal distillation. Heated to around 170 DegC for 5 hours with stirring.  After 5 hours, added 200ml water let cool and extracted into DCM.  Separated DCM layer from aqueous layer and removed most of the DCM by gentle heating.
Added residue (with some left over DCM) to a mixture of 16ml methanol and 150ml 15% HCL heated to 60DegC.  Evaporated residual DCM, then fitted reflux condenser and heated at around 80DegC for 2 hours with stirring. After 2 hours, let cool and washed with DCM.  DCM wash discarded.  Basified with 10% NaOH and 28ml raw MDA base fell out of solution to the bottom of the separating funnel. Extracted raw base with DCM, distilled the freebase and gased in xylene, yield 25g.

DF

Title: 46g MDP2P (@ 178.18g/mol) = 0.258mol yield 25g
Post by: ApprenticeCook on August 25, 2004, 02:18:00 AM

46g MDP2P (@ 178.18g/mol) = 0.258mol
yield 25g MDMA.HCl (@ 229.7g/mol) = 0.108mol
0.108mol / 0.258mol = 0.418 = 41.8% yield.

Not very good yields...
-AC

Title: Re: Not very good yields
Post by: methyl_ethyl on August 25, 2004, 04:21:00 AM

This is the "leucky" right.  Correct me if I am wrong but it is my assumption that if you are running leuckart's more than likely you are just really into the reaction, and not really into yields, or effciency.

After all most folks AFAIK, that can procure the reagents needed in the leukart, more than likely could procure the reagents for a higher yielding synthesis.  I could be wrong but this is how I see it, and is definitely my stance on the synth.  The Leucky was my first route to MDA, and although I have fond memories of it, I doubt I will ever run it again....

regards,

m_e

Title: leuckart: Formic acid - homemade Ammonia -...
Post by: ApprenticeCook on August 25, 2004, 06:59:00 AM

leuckart:
Formic acid - homemade
Ammonia - from any of the BILLIONS of OTC sources

Al/Hg:
HgCl2 - homemade
Al - duh...
MeAm - theres a few OTC ways or use nitro....

Just as OTC as each other, Al/Hg gives far better yields (unless you fuck it right up) than leuckart...
Just requires a bit more work with the Al/Hg and playing with a toxic material... thats my only hang-ups with it, but once the lovely product comes out all the worries go away....  ;D

-AC

Title: yeah,
Post by: hypo on August 25, 2004, 09:56:00 AM

i once tried a leuckart (not on a phenethylamine though) and on workup ended
up with 4 phases (3 liquid, 1 solid). i was impressed. but did get some 40%
in the end.  ;D

Title: i know one can make it better,
Post by: DoctorFeelgood on August 25, 2004, 02:02:00 PM

but for me it was ok, i just wanted to try mda. i did it half a year ago and i still have about 10g of it - it's not my favourite drug. i mixed it with mdma, consumed it in the evening, but the next day, i was still on mda - i hated this. i know one can do it better with nabh4 and there are also some improvements for the leuckart, which will increase the yield, that's why i told him to use TFSE, sure he will get a more detailled description of a higher yielding method.
greetings

Title: ApprenticeCook, can you explain how you
Post by: DoctorFeelgood on August 25, 2004, 02:15:00 PM

did the Al/Hg to get MDA ? I have read a lot of posts, that the Al/Hg works only with boro/cyanoborohydride, which are both very hard to get for me. but he normal al/hg with nitro is said to not work, but maybe you can post a working synth right here...
thanx in advance

Title: Formic acid
Post by: Chimitant on August 25, 2004, 10:24:00 PM

The Leuckart reaction can be done both without or with formic acid. The advantage of using formic acid is a lower reflux temperature and lower yields of by-products (although yields still will be low compared to other reductive aminations). Be sure that your reflux condensor is working OK otherwise you will loose formic acid in no time and end-up with a higher reflux temperature.

Title: No i didnt make MDA via Al/Hg, MDMA...
Post by: ApprenticeCook on August 26, 2004, 05:52:00 AM

No i didnt make MDA via Al/Hg, MDMA...
And of course you cant use Nitro to make MDA, nitromethane will reduce to methylamine and go on its way in Al/Hg.
This is a nice method for MDA Al/Hg:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/alhg.oxime.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/alhg.oxime.html)

with an 81% yield even.

-AC