Sciencemadness Discussion Board

Al/Hg - Salvageable?

Flip - 27-4-2010 at 08:35

Let's say that one has a ketone derived from dillapiole and they run a reductive amination via Al/Hg. There's only one problem.. they forget to add their amine. The Al/Hg goes along fine and they go about their business and extract this mixture with toluene, gas the toluene with HCl, and realize their mistake as the solution begins to turn dark.

Can this situation be salvaged?

Has the ketone been reduced to the alcohol? If so, what would be the best route back to the amine? If not, I suppose things would be pretty straightforward.

Thanks,

Flip

Melgar - 27-4-2010 at 11:34

I think that this individual should take a break from using the intended products typical of said reaction and perhaps his memory will improve. ;)

Still, I'm pretty sure you need metal hydrides to reduce ketones to alcohols, so there's a good chance your reaction didn't affect the ketone at all.

Flip - 27-4-2010 at 12:57

Thanks. That's what I thought but add HCl into the mix and the whole thing is just a mess. It just leaves one to wonder with all the heat given off in the reaction just what exactly would have been reduced. Water, I suppose, but it was run in anhydrous MeOH. I think the solution will just be to redistill. As a disclaimer, the position of the carbonyl may be different from where you're thinking. :P

DJF90 - 27-4-2010 at 13:41

Say hello to the pinacol coupling...

stateofhack - 29-4-2010 at 09:48

Quote: Originally posted by DJF90  
Say hello to the pinacol coupling...


hahah second that!

Bolt - 29-4-2010 at 13:36

I would just try to vac distill a small amount of your mess and see if you can get any ketone back. I might also try a bisulfite adduct.

Ephoton - 29-4-2010 at 13:50

al/hg will reduce a ketone to an alcohol though as stated above you will get some pinacol coupling
of the carbonyl from an al/hg of this substitued ketone.

I have salavaged other ketones from this kind of problem in the past though I always lost some.

I agree with bolt in that you should vac distill the tone :)

the nose will tell you everything then.

peach - 1-5-2010 at 02:30

Quote: Originally posted by Melgar  
I think that this individual should take a break from using the intended products typical of said reaction and perhaps his memory will improve. ;)


:o :D

Smoking around a lab is a bad idea as well. :P