Sciencemadness Discussion Board

magnesium amalgam

chemrox - 21-3-2016 at 17:10

It seemed like a likely item to come up on search but no joy. Has anyone had experience making magnesium amalgam? Better yet, any experience using it for reductions? Since there seems to be an affinity with halides as per Grignard reax it might reduce aromatic chlorides. Having said that I might a) be dead wrong and b) since chlorides are rather sluggish Grignard adducts am I barking at the wrong shrub? In any event I want to try it on loperamide as per another post I wrote today. It might also be a messy workup but the methods I tried as alternatives to PTH using Pd and K-propionate were all messy; especially the Zn methods.

Dope Amine - 25-3-2016 at 18:29

I've been trying (with difficulty) to follow your train of thought lately, with the dopamine vs. mu agonism and the 4-amino-1-phenethylpiperidine synthesis. I'd love to know what you're actually going after....

Anyway, I don't think Mg is going to work for you. I'd recommend doing a CTH with Pd/C and either potassium formate (+ water) or limonene, or Zn and ammonium chloride saturated THF. The first one worked for me with loperamide.



Attachment: CTH Transfer Hydrogenolysis of Aryl Halides.pdf (506kB)
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Attachment: reductive dehalogenation with Zinc.pdf (60kB)
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Attachment: Loperamide degradation.pdf (285kB)
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Attachment: CTH REVIEW -thorough.pdf (6.3MB)
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***Edited to remove double attachment of "CTH Transfer Hydrogenolysis of Aryl Halides.pdf" file and post "CTH Review.pdf" file instead.

Attachment: CTH Review.pdf (1.2MB)
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[Edited on 27-3-2016 by Dope Amine]

Dope Amine - 26-3-2016 at 19:16

I forgot about this until just now, but by the looks of the attached paper a catalytic amount of triethylamine and ethanol as the solvent seem to greatly increase the CTH activity of Pd/C.

Also, I would suggest considering Chan-Lam coupling (CuO and 3-pyridinylboronic acid or whatever's appropriate) if you intend to attach some kind of heteroaromatic group to the 4-amino.

Attachment: New Trends in Palladium-Catalyzed Transfer Hydrogenations Using Formic Acid.pdf (81kB)
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chemrox - 27-3-2016 at 13:12

Thanks! I have multiple interests going... I think I'm back to the one you recommended and thanks for the additional ref!

DJF90 - 28-3-2016 at 03:56

This might be of some interest Chemrox:

http://www.orgsyn.org/demo.aspx?prep=CV5P0998

Loptr - 29-3-2016 at 03:40

Quote: Originally posted by DJF90  
This might be of some interest Chemrox:

http://www.orgsyn.org/demo.aspx?prep=CV5P0998


This was a reaction I was considering to perform with 1,4-dichlorobenzene as the substrate, but I decided that 1,4-dihydroxybenzene would be a more interesting target. It's amazing what can be found at the local grocery and hardware store; a veritable OTC chemical paradise!

* I just recently started browsing the shelves at various stores that I visit to see what could be found. The other day I came across a kitchen cleaner containing a majority of diisopropylamine--my first thought was to attempt a preparation of lithium diisopropylamide (LDA)! :D


[Edited on 29-3-2016 by Loptr]

[Edited on 29-3-2016 by Loptr]