Author Topic: Reduction of PN2P with Zn/Hg  (Read 8681 times)

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Grignard

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Reduction of PN2P with Zn/Hg
« on: November 12, 2003, 10:43:00 AM »
In the book Amphetamine synthesis by Otto Snow, there is an reduction of nitrostyrene by the use of powdered zinc dust and mercuric cloride, then he just ad HCl and thats it! would this work for PN2P? It also tells qite alot about electrolytic reduction..  :P

Bandil

  • Guest
I have also read the Otto Snow book, and ...
« Reply #1 on: November 12, 2003, 11:07:00 AM »
I have also read the Otto Snow book, and although there are some good things inbetween most of it is crap, seen from our perspective. There are almost never mentioned anything about yields etcetc. It seems a bit "festerish"(i.e. not very good) so to speak  8) . There has been sporadic reports of successes with Zn/HCl reductions, but i don't think anything conclusive ever came out from it. I believe Sunlight wrote something on the topic, try using the search engine.

I think that Zn/HCl reductions of the nitropropenes are only attractive to the aspiring chemst, as they seem easy and OTC, but as with the bromosafrole + ammonia / methylamine it's no good in the long run, as there are no conclusive reports on either. Better save yourself the grief of failure, and go directly for the more established routes. The reagents might be a bit harder to get, but it is definately worth it.

Once you master those basics, it might be worth a shot to tweak the parameters of the aforementioned reactions and get some conclusive results.

Good luck!

Regards
Bandil


Grignard

  • Guest
Thanks.. Which method is the best for ...
« Reply #2 on: November 12, 2003, 11:27:00 AM »
Thanks.. Which method is the best for reduction of PN2P? bether to reduce it to P2P first by the oxime or Fe maybe?

Bandil

  • Guest
LAH is useable, but not nice to work with.
« Reply #3 on: November 12, 2003, 11:55:00 AM »
LAH is useable, but not nice to work with. I'd advice you to try out the IPA / water borohydrydide reduction followed by Zn / formic acid reduction. It's really easy to work with, and a lot of research has been done on the method.

Read the following three posts:

Post 465461

(Bandil: "Proof of concept!", Novel Discourse)
,

Post 465948

(GC_MS: "Reanalysis", Novel Discourse)
and

Post 465759

(GC_MS: "Confirmation", Novel Discourse)
. There should be enough information to start you up.

The only thing not so OTC about those procedures(given that you allready have the phenylnitropropene handy) is the borohydride. But it's not harder to get than hydroxylamine, which you would need for the oxime, so it's a really good option.

Regards
Bandil


Grignard

  • Guest
Yeeeeees!!! I must get some borohydride, the...
« Reply #4 on: November 12, 2003, 12:06:00 PM »

Vitus_Verdegast

  • Guest
about Zn/HCl
« Reply #5 on: November 12, 2003, 12:59:00 PM »
SWIM has tried it ala Sunlight and it works, but the workup is horrible. The last time it was like having to extract a can of paint.


Grignard

  • Guest
I tryed it once with Al/Hg and i only get red...
« Reply #6 on: November 12, 2003, 01:24:00 PM »
I tryed it once with Al/Hg and i only get red thick tar as usual.. And the white precipitate was horrible to filter. And i dont feel wery safe about that Hg mess.. :)

GC_MS

  • Guest
Zn/HCl doesn't work for alfa-methylnitrostyrenes
« Reply #7 on: November 12, 2003, 08:44:00 PM »
The Zn/HCl reduction does work for nitrostyrenes. Search The Hive and Rh's site for Leminger and you'll find what you need. I have made a post in the past where I tested it for mescaline. I have tried it several times afterwards and found yields to be circa 50%. I have to agree with Vitus though. Workup is a bitch.
This reduction does not work for alfa-methylnitrostyrenes, something which you should have found with TFSE as well. The Zn/HCl reduction will yield the ketone as a major and the amine as a minor compound (let's say 80-20%). I think I have posted something about that in the past as well, trying the Zn/HCl reduction of 4-methoxyphenyl-2-nitropropene. Anyway, I still remember that the reaction mixture consisted for the main part of 4-methoxyphenyl-2-propanone.


Antibody2

  • Guest
if you want a redxn with simple chemicals try...
« Reply #8 on: November 13, 2003, 04:54:00 AM »
if you want a redxn with simple chemicals try urushibara Ni. Ritter pulled off 50% with P2NP

The Zn/Hg redxn  was attempted on 2,5DMNS with discouraging results, antibody has nothing good to say about it


amine

  • Guest
I tried the Zn/HCl and failed mysteribly.
« Reply #9 on: November 13, 2003, 05:22:00 PM »
I tried the Zn/HCl and failed mysteribly. The work up is definitely a problem.

A wonder what it would be like if one had to mix the 25DMNS in a toulene solution,add a PTC, add some zinc,  drip the HCl into the solution...any ideas?

Antibody2

  • Guest
The Zn/HCl redxn runs fine on 2,5-DMNS (ca...
« Reply #10 on: November 14, 2003, 12:17:00 AM »
The Zn/HCl redxn runs fine on 2,5-DMNS (ca 40%), but it needs cooling throughout the entire rxn. It also needs to be worked up without delay.


Grignard

  • Guest
I really think reduction of this PN2P is a...
« Reply #11 on: November 17, 2003, 09:36:00 PM »
I really think reduction of this PN2P is a pain in the a.. But i have tryed this urushibura reduction and it really smells good.. but the result is just nothing! What about try Ni on Zn instead of using Al???? Like the big text on urushibura catalysts on rhodiums page? One thing i probably do wrong the last time was to add the NaOH wery fast under much evoulution of heat, cold this result in a nucleofilc atack on the amine, and substitute NH3 with OH or something, cause the hole shit smelled just like ammonia after i add this.? :P

Sunlight

  • Guest
More
« Reply #12 on: November 23, 2003, 08:18:00 PM »
Zn/HCl works fine for 2,5 DMNS, and yields are higher than 50 %, usually 60% and I have a report of a friend that used Leminger instructions with a 80 % yield. For nitropropenes, forget it.

Organikum

  • Guest
Leminger
« Reply #13 on: November 25, 2003, 03:24:00 PM »
is IMHO not the last word on Zn/HCl reductions.

someone please dig up this reference:
Krause: Chem. Ztg. 40, 810, (1916)

By using HCl in catalytic amounts - about 1/40th of theory - excellent to quantitative yields are achived in the reduction of (aromatic) nitrocompounds.

The reduction of chloropicrin using stochiometric amounts of HCl yielded mainly ammoniumchloride, by using the method described in the reference above quantitative yields of methylamine were achieved.
(from an article on chloropicrin - a warfare agent)

And "pling"?
hexamine to methylamine someone? LOL......

Rhodium

  • Guest
bridge the gap
« Reply #14 on: November 25, 2003, 04:38:00 PM »
How is the reduction of chloropicrin (CCl3NO2) with Zn/HCl related to the manufacture of methylamine from HMTA?

Organikum

  • Guest
both yield methylamine
« Reply #15 on: November 25, 2003, 05:19:00 PM »
both are reductions
and run smooth with much less HCl as theory and Zn.
and produce shitloads of ammoniumchloride if more HCl is used.

and I even propose:
HMTA + mucho more water as usual + mucho less HCl as usual -> methylamine in excellent yields + CO2
thats what the old french chemists did.
(perhaps they also used a metal pot - maybe, but dont think so)

I am not interested in the atoms in the soup.
I am hunting patterns.
Works fine btw.
LOL

lugh

  • Guest
Requested Article
« Reply #16 on: December 06, 2003, 12:01:00 AM »
Here's the requested article, Krause: Chem. Ztg. 40, 810, (1916):



:)


Organikum

  • Guest
in short
« Reply #17 on: December 07, 2003, 02:21:00 PM »
the article is the hit.

- reducing nitromethane to methylamine with iron/HCl or Zn/HCl in almost quantitative yields - the solution has to stay SLIGHTLY acidic what is accomplished by using 1,5molar HCl at 70°C in one hour.
- works for aromatic nitrocompounds in the same manner
- with not saltforming compounds 1/40th of theory HCl is to be used
- works also with acetic acid or H2SO4 so the reaction takes more time to start up

forget Leminger, Krause rulez !  ;)

and I say: this works with HMTA - hexamine too.

but as always there will be nobody listening and the mass production of ammoniumchloride will go on and on and on......  ::)  ::)

not in my flask so.... :)  ;D  ;D
ORG


Rhodium

  • Guest
How do you extrapolate?
« Reply #18 on: December 07, 2003, 07:20:00 PM »
and I say: this works with HMTA - hexamine too.

but as always there will be nobody listening and the mass production of ammoniumchloride will go on and on and on...


Not with my age-old procedure where (para)formaldehyde is added to the hexamine/HCl mixture to balance the equation... The "problem" with the hexamine procedure is simply  that there are too few formaldehyde equivalents available in HMTA per default.  By using formaldehyde as reducing agent instead of a dissolving metal, the workup will be far simpler.

And I still don't understand how you extrapolate from a nitro reduction to a hexamine reduction.

Organikum

  • Guest
workup
« Reply #19 on: December 07, 2003, 09:26:00 PM »
uhhh, steamdistillation into dil. HCl is a hassle for you, Rhodium who tells everybody to distill meth, ketone and whatnotelse?

This is astonishing.
I actually never heard of real good yields with your procedure so - please point me to a post where somebody used this successfully.
Also Chromic and RoundBottom who are known to be the ones most experienced in the "traditional" way with lousy yields sadly must be rather stupid not to do it this way.
And I actually dont believe Chromic and RB to be stupid - sorry.

For to know how I come to propose the nitroreduction also to work on hexamine as it works on chloropicrin - read the article and the reaction mechanism as it is told there and you might understand. Its the second equation in the article - not the first btw.