FireLion3 - 26-6-2014 at 13:56
I am planning to use aqeuous (ph14) Sodium Borohydride with a phase transfer and a hydride transfer catalyst (Ni 0 or Pd 0) to hydrogenate
1-Nitrobutane. Usually Borohydride can't reduce nitro groups to amines, but it can in the prescense of a transfer-hydrogenation catalyst.
For sodium borohydride to be used in an aqeuous solution it must be stabilized in a 14 pH solution....this can be made with 1M hydroxide.
My problem is that I think the Hydroxide would react with the acidic hydrogen on the 1-Nitrobutane to form the Enolate. If all of the hydroxide are
used up then the borohydride will become unstable. This could be remedied by using 2M hydroxide, but can CTH hydrogenate nitronates/enolates? My other
concern is if hydroxide forms with the nitroalkane then I will end up needed an eq molar quantity of hydroxide with some excess to keep the
borohydride stable :/
What should I do? I don't want to do a non-ptc reaction (without the base) because the yields are low and large excesses of borohydride are required.
[Edited on 26-6-2014 by FireLion3]
Crowfjord - 29-6-2014 at 14:14
Nitroalkanes can be reduced to amines using copper-modified sodium borohydride in ethanol. See the reference posted by Madscientist at the bottom of
the first page of the Al/Cu thread called "Reduction of organic compounds with sodium borohydride-copper (II) sulfate system." No need for PTC or base.
zed - 30-6-2014 at 13:22
Well, you have Borohydride. You could try a modification of the "Brown System". Wherein, the Nitrobutane is reduced to the Amine, via
hydrogenation with Pt, or Nickel Boride. Using NaBH4 as your source of hydrogen.
zed - 1-7-2014 at 15:49
This reduction might be possible via Hg/Al. Cheaper. More literature available.
PHILOU Zrealone - 2-7-2014 at 01:11
Why use such expensive reducers for simple nitroalcanes?
If the base/nitronate is your problem (of conscience) then go acidic...
Zn/HCl
Sn/HCl
SnCl2/HCl
Fe/HCl
Should do the job.