iloveloli
Harmless
Posts: 21
Registered: 8-8-2015
Member Is Offline
Mood: No Mood
|
|
Phenylalanine decarboxylation
i saw someone is asking about L-tryptophan decarboxylation.
so i think Phenylalanine can do decarboxylation too...
my problem is what solvent should i use??
(i am sorry about my eng is so bad
|
|
|
Nicodem
|
Thread Moved
27-9-2015 at 03:34 |
MeshPL
Hazard to Others
Posts: 329
Registered: 20-4-2015
Location: Universe
Member Is Offline
Mood: No Mood
|
|
Preferably one that has a high boiling point, is liquid in room temperature and dissolves phenylalanine. And doesn't react with it. So not a
haloalkane.
DMSO, or higher ethers may be good. (Not diethyl ether, that boils 35C or so, rather biphenyl, dibuthyl ethers)
Note that you're not guaranteed to succeed. You may try converting phelylalanine to it's copper salt first. Decarboxylation is not an easy thing. If
phenylethylamine is not too unstable you may just pyrolyse phenylalanine.
Try using the same methods as described for that decarboxylation of tryptophan.
There is also Barton decarboxylation, but it requires organotin compounds, radical initiation and complex hetrocyclic reagent to work.
Hope you're not attempting to make drugs.
|
|
|
morsagh
Hazard to Others
Posts: 187
Registered: 20-2-2014
Member Is Offline
Mood: No Mood
|
|
Problem is also that alpha-aminoacids can lose water before decarboxylation and produce 3,6-substituted 2,5-dioxopiperazine.
|
|
|
morganbw
National Hazard
Posts: 561
Registered: 23-11-2014
Member Is Offline
Mood: No Mood
|
|
I am just a little lost on what your are after but if you
use this search phrase in google, it will lead to quite a few hits.
It will at least give you something to read.
Leave the quotation marks off.
"Phenylalanine decarboxylation site: http://www.sciencemadness.org"
[Edited on 28-9-2015 by morganbw]
|
|
|
fluorescence
Hazard to Others
Posts: 285
Registered: 11-11-2013
Member Is Offline
Mood: So cold outside
|
|
Reaxys suggests using Cyclohexenon as solvent and catalyst, heating it to about 150°C for about an hour.
At least if you want to make Phenylethylamine from it. The following Paper is added:
https://www.jstage.jst.go.jp/article/cl1972/15/6/15_6_893/_a...
Haven't had time to download that Paper yet, but give it a try it might contain what you are looking for.
Dunno Reaxys sometimes calculates this stuff from other Educts and just assumes it would do the same
so unless it's not in Literature I wouldn't do it, but that Method using Cyclohexenon seems quite good
and is a quite new Article from 2006.
|
|
|
spankyetal
Harmless
Posts: 23
Registered: 24-7-2017
Member Is Offline
Mood: No Mood
|
|
decarboxylation solvents
Quote: Originally posted by iloveloli  | i saw someone is asking about L-tryptophan decarboxylation.
so i think Phenylalanine can do decarboxylation too...
my problem is what solvent should i use??
(i am sorry about my eng is so bad;)
|
From what I've read in the older literature the decarboxylation of PhAl. is a pyroletic degredation requiring no solvents. Just a distillation setup
to condense the 2- phenylethylamine. However, as one who appreciates the chemistry 2-PEA liquid is available on ebay. 4 oz. USP grade 65 samolies.
|
|
|
AvBaeyer
National Hazard
Posts: 644
Registered: 25-2-2014
Location: CA
Member Is Offline
Mood: No Mood
|
|
Very pure phenethylamine hydrochloride is widely available and cheap from supplement sites. No need to torture yourself with decarboxylations.
AvB
|
|
|
Assured Fish
Hazard to Others
Posts: 319
Registered: 31-8-2015
Location: Noo Z Land
Member Is Offline
Mood: Misanthropic
|
|
I don't mean to be the asshole of the thread but...
Use The Fucken Search Engine.
Litterally 2 months ago Melgar opened a thread on the topic of decarboxylation of alpha amino acids.
http://www.sciencemadness.org/talk/viewthread.php?tid=74727
Its even still on the first page of the organics section.
A viable method was also raised within the capsazepine thread.
http://www.sciencemadness.org/talk/viewthread.php?tid=73875&...
I think it is the same method from the paper given by fluorescence, only the idea was sourced from a different place.
https://erowid.org/archive/rhodium/chemistry/trp.decarbox.en...
It does not need to use cyclohexenone as a solvent but instead suggests using cyclohexanol as a solvent with cyclohenenone used catalytically.
It reports an 85% yield from the decarboxylation of α-Phenylalanine.
Nontheless i intend to carry out this reaction at some point soon, once i get the reagents together and find the time.
If you can find a suitable and cheap source of cyclohexenone then you could buy it but i would suggest preparing it by oxidation of cyclohexananol to
cyclohexanone, followed by alpha halogenation under acidic conditions of cyclohenanone to 2-halo-cyclohexanone, followed finally by halide elimination
using an alkali metal alkoxide.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
