Can i substitute the acetic acid in an
acid. Al/Hg reduct. ?
(f.e. with HCl etc.)
I have tried formic acid, but my substrate went red
while adding and I think its a bit strong.
oh, and btw
Hello to all Labrats.
I`m new on your fantastic board Pomzazed - 29-4-2010 at 09:53
"substrate" went red?
can you specify the reaction you were doing? There are too many reactant that can be reduced with Al amalgam so your question is quite unclear and I
cannot fetch more info.elsemka - 29-4-2010 at 13:27
I made the reaction
with beta-nitrostyren !
or can I make the reaction in neutral conditions too,
or is it too weak for nitrostyrenes ? DJF90 - 29-4-2010 at 15:21
Quote:
I made the reaction
with beta-nitrostyren !
Well theres a suprise...mr.crow - 29-4-2010 at 20:37
Welcome to the forum.
Please learn how to communicate effectively.elsemka - 30-4-2010 at 18:29
@ DJF90
I know its my first post, and indeed it`s no surprise
but when I look around here their are enough posts about reductions of
different nitrostyrens and even nitropropens, so wtf.
My problem is that I can`t find anything about the acidic al/hg red. on
nitrostyrens (or whatever ),
not so for any other reduction,oxydation,aldol-reactio..........
(organikum for the masses)
@mr.crow
I know how to communicate effect.,
but you can see the reactions by yourself.
My first posts are a bit opaque.
I will buy some acet. acid, when I need it but
I want to know what the acid cause in the reaction.
thx
elsemka - 1-5-2010 at 04:40
I think i have it.
The H2 works like a base, the acid is to buffer it.
Am I right on the path ?
Oh man, I don`t like theory DJF90 - 1-5-2010 at 07:11
:| Good luck getting H2 to take a proton off of anything.
What you're doing is dissolving metal reduction. Al/Hg is chemoselective for the unsaturated portion of the nitrostyrene, but excess will take you all
the way to the amine. There is no H2 involved in the reduction. In the dissolution of the Al/Hg, (typically solvent is H2O- or MeOH-THF - not AcOH)
electrons are formed. In the absence of organic material, these reduce the water/methanol to form molecular hydrogen. However, when reducable organic
material is present, they act upon the substrate, and the H+ ions formed in dissolution are used to protonate when required. Ephoton - 2-5-2010 at 09:06
you need an acid as solvent to reduce a nitrostyrene to amine. it will not reduce the double bond otherwise.
al/hg is not very reductive towards double bonds it will reduce a nitro in neutral conditions but requires
acidic conditions to reduce nitrostyrenes and oximes.
I have not heard of a substitute for acetic acid as the cosolvent.
though I would be very interested if someone had an acid that worked and still kept resonable yeilds. DJF90 - 2-5-2010 at 10:37
Ephoton: You obviously did not read my post. Aluminium amalgam is CHEMOSELECTIVE for reducing the C=C double bond of nitrostyrenes i.e. It does this
EASIER than reducing a nitro group itself. I wonder why I waste my (virtual) breath sometimes
), 
