jwarr
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Aluminium amalgamation
My understanding of the underlying reaction mechanism behind aluminum amalgamations is hazy at best. Could someone please point me in the direction
of a reference explaining what exactly is going on here?
In particular, I'm looking at the reductive amination of 3,4-(Methylenedioxy)phenyl-2-propanone with methylamine to the corresponding secondary amine.
If someone could elucidate the process here, I'd really appreciate it. How exactly does the methylamine attack the carbonyl oxygen? I'm assuming
there is a transitional state with the oxygen bonded to a H on the amine but beyond that I haven't a clue. Also, how is the corresponding imine
reduced by the Al/Hg?
All the literature I have read points to a very temperamental reaction. Why do the chemicals have to be mixed such a specific order? How is the
al/hg amalgamate scaled in relation to the chemicals being reduced? The only documents I've seen suggests scaling the procedure is not simply a
matter of increasing or decreasing reactants by a constant factor.
[Edited on 14-2-2010 by jwarr]
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Nicodem
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Quote: Originally posted by jwarr  | | Could someone please point me in the direction of a reference explaining what exactly is going on here? |
It is called reduction reactions. In this particular case it is about reducing imines formed in situ from a carbonyl compound and an amine. There is
plenty literature, even monographs, on reductions and such reductions of imines.
| Quote: | | How exactly does the methylamine attack the carbonyl oxygen? |
Imine formation
| Quote: | | Also, how is the corresponding imine reduced by the Al/Hg? |
Dissolving Metal Reductions of Pi-Electron Systems
| Quote: | | All the literature I have read points to a very temperamental reaction. Why do the chemicals have to be mixed such a specific order?
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Exothermic enough reactions usually are temperamental. There is nothing unusual there. Chemicals need to be mixed in a specific order because you are
performing a reaction where things need to occur inside the framework of specific conditions.
| Quote: | | How is the al/hg amalgamate scaled in relation to the chemicals being reduced? The only documents I've seen suggests scaling the procedure is not
simply a matter of increasing or decreasing reactants by a constant factor. |
To scale up the reaction you first go to the university to study chemical engineering. Then when you finish and get the diploma you realize that the
only way to scale up some reactions is not to perform them and do others instead. That is the easy way. But you can also do it differently and end up
in troubles which may range from minor spillovers to glass shrapnels inside your body parts.
PS: It took me 5 minutes to find you the pedagogic material cited just by googling around (and I only checked the first few hits!). I suggest you to
take a similar approach any time before opening new threads, or else do so in Beginnings section where I'm moving this.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Nicodem
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Thread Moved
14-2-2010 at 13:37 |
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