Author Topic: TMA-2 by low-pressure catalytic hydrogenation.  (Read 5841 times)

0 Members and 1 Guest are viewing this topic.

Rhodium

  • Guest
Nitroalkene CTH
« Reply #20 on: October 15, 2002, 09:03:00 PM »
There are very few examples of nitrostyrene CTH's in the literature, but there are several on reducing nitro groups and oximes. I believe that those are applicable to nitrostyrenes too, as reducing the nitro group of a nitroalkene first creates the oxime, which then can be further reduced to the amine.

See the CTH documents on my page to find references to further reading.

Sunlight

  • Guest
CTH oxime to amine
« Reply #21 on: October 15, 2002, 11:53:00 PM »
Could you post an example of oxime amine CTH reduction ?

Rhodium

  • Guest
CTH Oxime Reduction
« Reply #22 on: October 16, 2002, 01:07:00 AM »

hest

  • Guest
Amph
« Reply #23 on: October 16, 2002, 01:32:00 AM »
2g phenylnitropropen was disolved in 50mL ethanol with 5mL acetic acid and 25mg Pd/C. The flask was evacuated and put under hydrogen at atmospheric presure. After the hydrogen uptake was stopped the solution was filtered throug celit, some DCM was added and then washed with NaHCO3(aq), dryet with MgSO4 and evaporated in vaco, disolved into 50mL ethanol and 1g RaNi was added, the hydrogenation was repeted and the amph was worked up as usual. Yeald 1,6g amphetamin almost pure on GCMS, also present was 5% N-formyl-amphetamin.

Barium

  • Guest
Great work hest!! I assumed the method would be ...
« Reply #24 on: October 16, 2002, 03:04:00 PM »
Great work hest!!

I assumed the method would be useful for regular phenylnitropropene but you proved it  ;D

Edit
You can cut down on the volume of solvents big time. For 10g phenylnitropropene you do not need more than 20-25 ml EtOH at the most. I wonder how the N-formyl was formed.


Catalytic hydrogenation freak

Barium

  • Guest
Comments anyone?!
« Reply #25 on: October 18, 2002, 05:15:00 PM »
Hest got an almost quantitaive yield of amphetamine here and no one but me has replied.... :o

Catalytic hydrogenation freak

Rhodium

  • Guest
Spend 15 min of your day writing a proper report
« Reply #26 on: October 18, 2002, 05:51:00 PM »
I believe the writeup was just too sketchy, I missed its significance written like that, with very few procedural details, no yield calculation etc... Usually bad writeups equals bad science...

If doing a 1 atm hydrogenation, how do you tell when hydrogen uptake has ceased?

The N-formyl-amphetamine is probably easily formed from the formate salt.

hest

  • Guest
Hydrogenation
« Reply #27 on: October 19, 2002, 01:21:00 AM »
yea,yea,yea.
I know the writing is bad, dammm has so littel time these dayes. The nitropropen was disolved in ethanol in a 100mL round flask, then mounted on a system with glasstubes filled with wather, the wather was then presed out of the system into a higer mounted resevoar by hydrogen gass, when the reaction use hydrogen the wather will raise into the glass tubes where you can see how much hydrogen the reaction has used, and when it stops. I guess this is standard equipment in a good lab. The grama and spelling is, as usual, hoples. I don't care.
I don't thing a step by step writeup is nessecery, this is just a hint abouth the power of the combination of too catalyst. I might try to mix them and see wath happend's

Barium

  • Guest
I would also very much like to have more details ...
« Reply #28 on: October 19, 2002, 12:57:00 PM »
I would also very much like to have more details from hest. We just have to teach this bee how thing should be done. If he doesn´t comply it´s off to Osmiums and Hey_mans dungeon of pain  ;)

How to tell when the hydrogen uptake has ceased? Either use a manometer and check when the pressure drops ceases, or have some sort of bubble device between the hydrogen reservoir and the reaction vessel.

Why is the N-formylamphetamine formed? There was no formate used.

Catalytic hydrogenation freak