Author Topic: Catalytic Hydrogenation of Ephedrine  (Read 3436 times)

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bumblebeetuna

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Catalytic Hydrogenation of Ephedrine
« on: November 10, 2000, 04:42:00 AM »

C10H15N

  • Guest
Re: Catalytic Hydrogenation......
« Reply #1 on: November 10, 2000, 08:43:00 AM »
-ok 3%,5% or 10% is fine. Pd/C is a catalyst, witch means
 that your 5% will only make things go quicker.

its only a matter of time. 8)

bumblebeetuna

  • Guest
Re: Catalytic Hydrogenation......
« Reply #2 on: November 10, 2000, 09:46:00 AM »
ok, any ideas on making pressurised h2?  I was thinking conc H2SO4 + Mg  inside on old oxygen tank with a pressure gauge....I gues i would have to know the exact cap of the tank, ... even then is that really safe????

terbium

  • Guest
Re: Catalytic Hydrogenation......
« Reply #3 on: November 10, 2000, 01:39:00 PM »
It is stainless steel not steal.

It is hydrogenate not hydrate

There are several procedures on Rhodium's site that have serious errors or, IMHO, just plain won't work. This procedure for hydrogenating ephedrine is one of them.

I like the part about sucking the air out of the vessel by "mouth suction" - ROTFLOL!

Most people wouldn't even use vacuum to rid the reactor of air - even if they had something better than mouth suction. Instead purge with nitrogen to remove the oxygen then purge with hydrogen to remove the nitrogen.

Ballistic

  • Guest
Re: Catalytic Hydrogenation......
« Reply #4 on: November 10, 2000, 01:47:00 PM »
What is the error in this rxn? And how could it be fixed?
I was going to try it because it used easy to obtain reagents.


The rain in Maine falls mainly down the drain.

serodronin

  • Guest
Re: Catalytic Hydrogenation......
« Reply #5 on: November 10, 2000, 01:54:00 PM »
this synthesis is a little sketchy, but the concept of it could be modified to make it work.  you would have to use chloroephedrine for it to work.  there are plenty of better synthesis out there for hydrogenation using palladium catalysts.  I personally don't trust any synthesis that I can't find in a patent.  You will need more than 30 psi to pull off a reaction like this.  I usually shoot for about 60psi(5atm).  also, every reaction of this nature I've seen used glacial acetic combined with another strong acid(H2SO4,HClO4, etc.)  no everclear mentioned.

terbium

  • Guest
Re: Catalytic Hydrogenation......
« Reply #6 on: November 10, 2000, 02:01:00 PM »
There is an old journal article that claims hydrogenation of ephedrine to methamphetamine but they used concentrated HCL, Raney Nickle and high temperature and pressure. I am very suspicious of these claims of doing it in dilute or weak acids and at low temperatures and pressures.

serodronin

  • Guest
Re: Catalytic Hydrogenation......
« Reply #7 on: November 10, 2000, 02:06:00 PM »
I read that article, and I think it was wrong also.  they claimed that reducing ephedrine resulted in amphetamine, and reducing norepinephrine produced methamphetamine.  this is backwards.  here is one I dug up:

Kindler et al., The Mechanisms of Chemical Reactions. X. Preparation of Phenyl-
and Cyclohexylalkylamines by Hydrogenation. Justus Liebigs Ann. Chem., 560,
215-21 (1948); C.A. 43: 1025g (1949).

It was found the hydrogenation of ephedrine to the corresponding amine is faster
with strong acids, such as H2SO4 and HClO4. Amino alcohols (such as ephedrine
and phenylpropanolamine) were hydrogenated only slowly in the absence of acid.
The use of H2SO4-H2O was better than that of H2SO4, avoiding reduction to H2S
and catalyst poisoning. The use of HClO4 in large amounts caused reduction of
C6H5 to C6H11 (the benzene ring was reduced to a cyclohexane ring).
(+)-Phenylisopropylmethylamine (PhCH2CHMeNHMe) was prepared in 95% yield as the
crude hydrochloride salt from 4 g. ephedrine hydrochloride, 90 cc. acetic acid,
4.7 g. 84% H2SO4, and 1 g. palladium wool. M.p. 166-8°, m.p. 182° (from
chloroform and ethyl acetate).

I don't notice any obvious errors in this logic.  also, I believe that Pd/C or Pd/BaSO4 would work fine as catalysts.  I am assuming that this reaction needs to occur under pressure and with somewhere between 60-90C temperature.

Ballistic

  • Guest
Re: Catalytic Hydrogenation......
« Reply #8 on: November 10, 2000, 02:40:00 PM »
So what you guys are saying is that this rxn produced something but it wasn't meth. All the other rxn of this type
did include acetic acid. Would there be something you could
substitute for acetic acid that one could produce or acuire
without going to a chem store?


The rain in Maine falls mainly down the drain.

serodronin

  • Guest
Re: Catalytic Hydrogenation......
« Reply #9 on: November 10, 2000, 02:55:00 PM »
they make something, but it ain't meth.  just gives you a buzzy headache you wish would go away.

glacial acetic acid is kept in quantity at photo supply stores.  really simple to get, just go in and pay cash.  no questions asked.  if you're really paranoid or can't find a photo supply store, go to the grocery store and get white vinegar.  you can distill it out from there.

WizardX

  • Guest
Re: Catalytic Hydrogenation......
« Reply #10 on: November 10, 2000, 03:39:00 PM »
The easiest way to make H2 gas is Aluminium and Sodium hydroxide solution (1M). The H2 gas can then be compressed into a gas cylinder while cooled in ice.

placebo

  • Guest
Re: Catalytic Hydrogenation......
« Reply #11 on: November 10, 2000, 05:08:00 PM »
This is KrZ's write-up called "Mastermind" I believe.
I am not sure, but I thought it had been tried and was succeful by others, but I may just have an over-active imagination and a un-natural need to stroke KrZ's ego. I am sure Rhodium would not have put it up on his site if it had no merit and obvious errors. But stranger things have happened! Look at the mole on Stonium's bum.


Wanna do the rumpy pump?

terbium

  • Guest
Re: Catalytic Hydrogenation......
« Reply #12 on: November 10, 2000, 06:18:00 PM »

I am sure Rhodium would not have put it up on his site if it had no merit and obvious errors.


How about the catalytic hydrogenation of phenylalanine to amphetamine that is on Rhodium's site. Does anybody really think that that works?

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



Another one I like is the rP/I reduction procedure that calls for placing the iodine and rP together in a ball mill so that they will be "thoroughly mixed".

And then there is the procedure we are discussing here that calls for removing the air from the hydrogenation reactor by "mouth suction". This would be funny if it weren't that some people will actually believe it.


KrZ

  • Guest
Re: Catalytic Hydrogenation......
« Reply #13 on: November 12, 2000, 05:23:00 PM »
That reaction is an exact duplicate of the reference which someone posted only days before, I will see if I can find it.  Mouth suction is a joke for idiot meth cooks, like all those warnings you see about mouth pipetting that are still around today even though it hasn't been done in decades.

Organikum

  • Guest
for completeness
« Reply #14 on: December 23, 2002, 10:40:00 PM »
ok, this is a quite old thread but I want to add something for not misleading bees on search.

The german

Patent DE968545

by Knoll AG from 1958 states that the by in post

Post 68517

(serodronin: "Re: Catalytic Hydrogenation......", Stimulants)
cited reference

Kindler et al., The Mechanisms of Chemical Reactions. X. Preparation of Phenyl-and Cyclohexylalkylamines by Hydrogenation. Justus Liebigs Ann. Chem., 560, 215-21 (1948); C.A. 43: 1025g (1949).


is wrong as this will not work as described with H2SO4.
The patent further describes a ephedrine.HCl reduction with in GAA solved HCl and Pd sponge as catalyst. The catalyst/substrate ratio is insane. The procedure can be modified by  using 10%Pd/BaSO4 or 10%Pd/C as catalyst in a much lower ratio and  adding small amounts of 70% HClO4 (which has to be diluted in GAA before addition). With this modifications it is a very good yielding synth for clean substrates.

ORG


now or never

Rhodium

  • Guest
Catalytic Hydrogenation of Ephedrine to Meth
« Reply #15 on: May 18, 2004, 01:05:00 PM »
Über die Darstellung von ?-Aryl-alkylaminen
Karl Wilhelm Rosenmund & Erwin Karg

Chem. Ber. 75, 1850-1859 (1942)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/ephedrine.hydrogenation.rosenmund.pdf)

Mentioned before in:

Post 71342 (missing)

(serodronin: "Preparation of B-arylalkylamines", Methods Discourse)
(Contains english abstract of this article)

Post 269642 (missing)

(MethKat: "paladium ingot", Stimulants)

____ ___ __ _

Studien über den Mechanismus chemischer Reaktionen. X.
Phenyl- und Cyclohexyl-alkylamine durch Hydrierung

Karl Kindler, Bruno Hedemann, Ernst Schärfe

Ann. Chem. 560, 215-221 (1948)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/ephedrine.hydrogenation.kindler.pdf)

Mentioned before in:

Post 68517

(serodronin: "Re: Catalytic Hydrogenation......", Stimulants)
(Contains english abstract of this article)

Post 359515 (missing)

(Chicken: "This refernce", Stimulants)

Post 392325

(Organikum: "for completeness", Stimulants)