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

Printable Version  
Author: Subject: Synthesis of n-alkylated amino acids
stoichiometric_steve
National Hazard
****




Posts: 827
Registered: 14-12-2005
Member Is Offline

Mood: satyric

[*] posted on 29-9-2007 at 08:02
Synthesis of n-alkylated amino acids


in Synth.Comm., 32(3), 457-465 (2002), a nice method for n-methylation of amines is given. i posted the ref in solos "methylation problems" thread.

the authors use paraformaldehyde and oxalic acid dihydrate at 100°C as methylation and reduction agent. if this method would also fit for amino acids, which are commonly methylated by Schiff base formation with benzaldehyde and subsequent methylation with nasty (nasty!!) dimethyl sulfate, the latter could be avoided.

moreover, does anybody know if alpha-ketocarboxylic acids can be reductively aminated with aliphatic amines as in standard procedures for ketones, or are there any problems that need to be solved?

[Edited on 29-9-2007 by stoichiometric_steve]
View user's profile View All Posts By User
solo
International Hazard
*****




Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline

Mood: ....getting old and drowning in a sea of knowledge

[*] posted on 29-9-2007 at 15:55


This recent post may be of interest to you posted in articles of interest in the reference section......solo

-----------------------------------------------------------------------------------------

Reductive methylation of primary and secondary amines and amino acids by aqueous formaldehyde and zinc
Renato A. da Silva, Idalia H. S. Estevam and Lothar W. Bieber
Tetrahedron Letters 48 (2007), 7680-7682

Abstract
Amines can be methylated when treated with formaldehyde and zinc in aqueous medium. Selective mono- or dimethylation can be achieved by proper choice of pH, stoichiometry and reaction time. This method can also be applied for amino acids.


https://sciencemadness.org/talk/viewthread.php?tid=5805&...



[Edited on 30-9-2007 by solo]




It's better to die on your feet, than live on your knees....Emiliano Zapata.
View user's profile View All Posts By User
stoichiometric_steve
National Hazard
****




Posts: 827
Registered: 14-12-2005
Member Is Offline

Mood: satyric

[*] posted on 30-9-2007 at 07:31


wow, solo! Thanks alot.

now, is there a separation method (besides electrophoresis) which is applicable to multigram batches of amino acids?
View user's profile View All Posts By User
Eclectic
National Hazard
****




Posts: 899
Registered: 14-11-2004
Member Is Offline

Mood: Obsessive

[*] posted on 30-9-2007 at 12:30


Liquid-solid chromatography. Ion exchange chromatography.

Google "amino-acid separation"

[Edited on 9-30-2007 by Eclectic]
View user's profile View All Posts By User

  Go To Top