Aluminium amalgam (Al/Hg) Summary

[mixxxman]

nu. nu va funcționa... "de ce?"

pentru că elementul folosit în această reacție este aluminiul !
activitatea mercurului este de a crea un amalgam. și în acest fel să ia de pe lay de "alumine (oxidarea naturală din aer pe aluminiu")

-pentru alte modalități de a obține o amină este :

*LiAlH4 (Lithium aluminum hydride), mai puțin toxic, destul de instabil/ greu de găsit.... ușor dacă ești profesionist pentru că este una din cele mai ușoare reduceri.

*sau cuplul Zn/Ni dar nu am încercat această metodă


dacă altcineva are alte informații ar fi frumos să le împărtășească și aici.

 

[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]

În locul dvs. aș testa pur și simplu cu o încărcătură mică dacă aveți galiu disponibil și aș raporta rezultatul aici.
Galiul formează un amalgam cu aluminiul la fel ca mercurul și produce hidrogen, dar există și unele diferențe la nivelul electronilor care fac imposibilă înlocuirea completă a mercurului cu galiu.

 

[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.