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

Printable Version  
Author: Subject: Ideas needed - Decarboxylation of Amino Acids
un0me2
aliced25 sock puppet
***




Posts: 205
Registered: 3-2-2010
Member Is Offline

Mood: No Mood

[*] posted on 19-6-2010 at 17:20
Ideas needed - Decarboxylation of Amino Acids


I've been looking around for a while now and despite there being a lot on the decarboxylation of carboxylic acids to the alkane with one less carbon (or other strategies), or the decarboxylation of amino acids to nitriles/aldehydes...

I cannot find anything on the decarboxylation of amino acids to the relevant amine that don't use fairly high-end reducing agents (eg like so).

What I'd like to know, is if anyone here has any good ideas for the decarboxylation of y-aminobutyric acid or B-alanine to give n-propylamine or ethylamine respectively?

Best kudos going to simplest routes as usual, personally I think a thermal route using a ketone, but I may be wrong, it might be that the destructive distillation of the copper salt of the amino acid might be the better option...

I'm just looking to see if anyone else has considered it:cool:
View user's profile View All Posts By User
Mildronate
National Hazard
****




Posts: 428
Registered: 12-9-2009
Member Is Offline

Mood: Ruido sintetico

[*] posted on 19-6-2010 at 23:51


To my mind its not cheap method. Some info http://www.erowid.org/archive/rhodium/chemistry/trp.decarbox...
View user's profile View All Posts By User
gardenvariety
Harmless
*




Posts: 41
Registered: 19-1-2010
Member Is Offline

Mood: No Mood

[*] posted on 20-6-2010 at 10:24


GABA isn't an alpha-amino, which might prevent the alpha-amino decarbox reactions from working the same way. I have some alanine that I will get around to turning into ethylamine, but haven't bothered yet. I had fairly good results on tryptophan with different enones, a bit better results from carvone than from pulegone.

The major problem with the ketone decarbox is the solubility of the amino acid. I haven't looked into it, but a PTC of some kind would be ideal.
View user's profile View All Posts By User
Mildronate
National Hazard
****




Posts: 428
Registered: 12-9-2009
Member Is Offline

Mood: Ruido sintetico

[*] posted on 20-6-2010 at 12:42


But amino acids are expensive
View user's profile View All Posts By User
gardenvariety
Harmless
*




Posts: 41
Registered: 19-1-2010
Member Is Offline

Mood: No Mood

[*] posted on 20-6-2010 at 13:10


Amino acids are dirt-cheap and readily available in most any biomass on the planet.
View user's profile View All Posts By User
Nicodem
Super Moderator
*******




Posts: 4230
Registered: 28-12-2004
Member Is Offline

Mood: No Mood

[*] posted on 20-6-2010 at 13:29


Quote: Originally posted by un0me2  
What I'd like to know, is if anyone here has any good ideas for the decarboxylation of y-aminobutyric acid or B-alanine to give n-propylamine or ethylamine respectively?

Best kudos going to simplest routes as usual, personally I think a thermal route using a ketone, but I may be wrong, it might be that the destructive distillation of the copper salt of the amino acid might be the better option...

You can not use any such thermal route, with a ketone catalyst or without it, because gamma-aminobutyric acid and beta-alanine are not alpha-amino acids (obviously, their names already say so!). So the imines they form with the ketones can not lead to decarboxylation. Though, in principle at least, due to a particular tautomerization property of imines (C=N-CH <=> CH-N=C), the imines of beta-amino acids might decarboxylate via the beta-imino carboxylic acid intermediates, but I have never seen this mentioned in the literature (but neither have I searched).
The only decarboxylation reaction that is general for many types of carboxylic acids (provided the other functional groups are properly protected for the steps involved) is the Barton decarboxylation. The primary amino groups needs to be protected.




…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)

Read the The ScienceMadness Guidelines!
View user's profile View All Posts By User
solo
International Hazard
*****




Posts: 3883
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 20-6-2010 at 13:55


...this might help,...solo
--------------------------------------------------------
One-pot Sequence for the Decarboxylation of a-Amino Acids
Bernard T. Golding
Synlett
2003, No. 4, 542–546




Abstract:
Treatment of an α-amino acid with N-bromosuccinimide
in water at pH 5 or in an alcoholic-aqueous ammonium chloride
mixture, followed by addition of nickel(II) chloride and sodium
borohydride, effected an overall decarboxylation via an intermediate
nitrile to afford the corresponding amine in good yield.

Key words: α-amino acid, nitrile, amine, decarboxylation

Attachment: aminoacid.decarboxylation.pdf (66kB)
This file has been downloaded 676 times





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




Posts: 4230
Registered: 28-12-2004
Member Is Offline

Mood: No Mood

[*] posted on 20-6-2010 at 14:00


Solo, that is the paper linked in the original first post by un0me2, but unfortunately it has no relevance for his question (decarboxylation of beta- and gamma-amino acids), because it is a procedure that can only work on some alpha-amino acids (see the mechanism).
View user's profile View All Posts By User
zed
International Hazard
*****




Posts: 2273
Registered: 6-9-2008
Location: Great State of Jefferson, City of Portland
Member Is Offline

Mood: Semi-repentant Sith Lord

[*] posted on 20-6-2010 at 20:54


So, there....Decarboxylation of Beta- Aminoacids, isn't very likely. However, if you wish to produce Ethylamine from ordinary Alanine, you probably can. Also, to my recollection, B-Alanine is spendy, and Alanine itself is quite inexpensive.

B-Alanine is sometimes offered for sale as a bodybuilding supplement, which may in some locales, make it more easily accessible than ordinary Alanine.....
View user's profile View All Posts By User

  Go To Top