Aluminium amalgam (Al/Hg) Summary

[mixxxman]

Não. Não vai funcionar... "Porquê?"

Porque o elemento usado nesta reação é o alumínio!
o trabalho do mercúrio é criar uma amálgama. e desta forma tirar a camada de "alumina (a oxidação natural do ar sobre o alumínio")

-para outras formas de amina é :

*LiAlH4 (hidreto de lítio e alumínio), menos tóxico, bastante instável/difícil de encontrar.... fácil se for um profissional porque é uma das reduções mais fáceis.

*ou o par Zn/Ni, mas eu já tentei este método


se alguém tiver outras informações, seria bom partilhá-las aqui também.

 

[waltjr5858]

Actually the lithium aluminum hydride is absolutely not the easiest reduction. I have hundreds of grams of that stuff and it's very easy to buy. I followed protocol exact same Reaction Time same exact amounts and the product is at best a 30% yield and it is all kinds of mixed with side products... yes it will reduce the double bond and the Nitro group but it leaves behind a ton of oxime... hydroxylamine and whatever else. I think the best reduction is the aluminum amalgam but that reaction is extremely finicky and if you can't get the amalgam perfect it won't go. Then we have the copper and borohydride which is great but I found that the laurelhydride has to be pretty damn fresh.

 

[waltjr5858]

Borohydride.... I have definitely wasted hundreds of grams of p2np on all different type of reactions. Another fairly clean way which is posted on this site is using zinc but the directions as they are posted do not work and I believe the poster that put them up said he just found them on the Internet and was going to give them a try. Using tin 2 chloride well absolutely give high yields of ketoxime and absolutely no acid needs to be added just the tin and the p2np. Allow that to run for maybe an hour or so and the exothermic reaction will come back to room temperature and you can kind of use their instructions for extraction for the next step. The Next Step requires an adjustment from what they put otherwise yes the oxime will go to amine but the double bond will remain. Use zinc and glacial acetic acid but take it up to reflux for 4 hours and that will saturate the double bond. A lot of write-ups say it will tolerate the double bond but they are also only doing 5 minute reactions to reduce the oxime to Amine and leaving the double bond. Another poster on the reaction on here somewhere used glacial acetic acid and a little bit of HCL when he did it and was successful. I tried it both ways with a dash of HCL on one maybe 10 mL to the whole reaction and just with GAA. Both fully successful. But more work than the aluminum amalgam. Although that damn amalgam can be tough to get right

 

[ACAB]

No vosso lugar, eu testaria simplesmente com uma pequena carga se têm gálio disponível e comunicaria o resultado aqui.
O gálio forma uma amálgama com o alumínio, tal como o mercúrio, e produz hidrogénio, mas existem também algumas diferenças ao nível dos electrões que tornam impossível substituir completamente o mercúrio pelo gálio.

 

[waltjr5858]

Exactly... this reaction is an electron swap between the aluminum and p2np. The hydrogen is actually bad for the reaction. But if the amalgam is right it will go.