Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2
Author: Subject: reductive am. why inert atmosphere?
chemrox
International Hazard
*****




Posts: 2953
Registered: 18-1-2007
Location: UTM
Member Is Offline

Mood: LaGrangian

[*] posted on 24-10-2010 at 00:53


Yes that would be a problem with alkane gasses wouldn;t it. @nicodem thanks for the merge sorry for doubling. I see the experience has been reduced yields with aldehydes. I was working more recently with a ketone and got nearly theoretical yields in air with water removal. So if I can make the imine and reduce it with NaBH4 in atmosphere does it follow the STAB procedure would work well in air with the same ketone? Or is there something about taking the water out with acetic acid that makes the imine more labile to oxidation? This doesn't seem intuitively correct. ie if it works with NaBH4/-H2O in air so should it be with STAB/acetic but since costly reagents are involved I definitely want as much real-world advice on this as I can get.



"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
View user's profile View All Posts By User
Methansaeuretier
Harmless
*




Posts: 45
Registered: 24-5-2010
Location: Europe
Member Is Offline

Mood: strongly alkaline

[*] posted on 24-10-2010 at 08:32


Btw. does STAB work also for dialkylation? Under which conditions?
View user's profile View All Posts By User
jon
National Hazard
****




Posts: 459
Registered: 11-1-2006
Member Is Offline

Mood: paranoid distrustful apprehensive

[*] posted on 25-10-2010 at 11:13


pretty much the same thing as reductive amination using primary amines.
only the double bond is on the carbon it's called an enamine.
it just occured to me STAB is'nt a way around azetropic distillation of the amine and the ketone because STAB is readily decomposed by water.
the only way around that is sodium cyano boro hydride.
View user's profile View All Posts By User
Methansaeuretier
Harmless
*




Posts: 45
Registered: 24-5-2010
Location: Europe
Member Is Offline

Mood: strongly alkaline

[*] posted on 25-10-2010 at 12:31


Quote: Originally posted by jon  
pretty much the same thing as reductive amination using primary amines.
only the double bond is on the carbon it's called an enamine.
it just occured to me STAB is'nt a way around azetropic distillation of the amine and the ketone because STAB is readily decomposed by water.
the only way around that is sodium cyano boro hydride.

STAB does defenitly work also without azeotropic destillation. I've done it myself.
View user's profile View All Posts By User
jon
National Hazard
****




Posts: 459
Registered: 11-1-2006
Member Is Offline

Mood: paranoid distrustful apprehensive

[*] posted on 25-10-2010 at 16:10


good to know
View user's profile View All Posts By User
 Pages:  1  2

  Go To Top