Author Topic: CHEM_GUYS Urushibara  (Read 2514 times)

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Knoevenagel

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CHEM_GUYS Urushibara
« on: March 29, 2002, 12:37:00 AM »
Hi

I´ve read CHEM_GUYS Urushibara reduction of P2NP to amphetamine on the Rhodium page. This method almost seem to good to be true!!

How can it possibly reduce both the nitrogroup and the double-bond?? HOW DOES IT WORK???
Isn´t any external source of pressurized hydrogen necessary? (Like for example Raney nickel)? Or does it like Al/Hg amalgam reduction function through so called "internal electrolytic reduction"

Does anyone know if CHEM_GUYS method has been tested or verified by someone else than himself?

IF ANYBODY COULD CLARIFY FOR ME I WOULD BE ETERNALLY GRATEFUL/ Knoevengel

Rhodium

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Urushibara Mechanism
« Reply #1 on: March 29, 2002, 02:03:00 AM »
The Aluminum reduces the NiCl2 to very finely divided nickel metal, which precipitates in the solution, and acts as a heterogenous hydrogenation catalyst. Excess aluminum is decomposed in the water forming Al3+ and hydrogen, which is adsorbed to the nickel surface and performs the hydrogenation.

If you perform a search on the Hive for "Urushibara" you will find an immense amount of information on possible reductions and the theory behind it. It is a very promising method.

Knoevenagel

  • Guest
Thanks man
« Reply #2 on: March 29, 2002, 10:53:00 AM »
Rhodium!

THANKS for this elucidation.

I suspected the H2-adsorption but didn´t think it could be done with just the H2-bubbling Aluminum.

If this method works why the hell are scientist bothering with external H2-sources and pressure reaction vessels???

Rhodium

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Urushibara Mechanism
« Reply #3 on: March 29, 2002, 11:11:00 AM »
Using H2 is less work, and is much better suitable for large scale synthesis. It is also cheaper and much better explored. But Urushibara could be the future for hobbyists.

Flinger

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Metal ZN/NI/etc
« Reply #4 on: March 29, 2002, 11:35:00 PM »

foxy2

  • Guest
hilarious
« Reply #5 on: March 31, 2002, 12:01:00 AM »
For some reason that last post made me bust up laughing
(Rated as: misinforming)
;D  ;D  ;D



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