brainetix
Harmless
Posts: 4
Registered: 6-4-2006
Member Is Offline
Mood: No Mood
|
|
Separation of 2-Phenylpropanal and the ketone?
Maybe someone knows this rxn from the old HIVE Board. You will get a mix of the aldehyd and the ketone, wich could not be separated by distillation.
But the aldehyde could be oxidized to the propionic acid wich is then washed with dil. aqu. NaOH to form the water soluble salt...
But wich oxidizing compound could be used? I know that KMnO4 or Sodium dichromate works, but this is not avaliable to my friend..
Are there any other (OTC) oxidizers, wich could be used to oxidize the aldehyde without affecting the ketone? Will 30% H2O2 work?
|
|
|
Douchermann
Hazard to Others
Posts: 117
Registered: 11-10-2005
Location: Illinois, USA
Member Is Offline
Mood: No Mood
|
|
KMnO4 should be available at sears. As for the hydrogen peroxide, I believe that you'd need special conditions for that concentration. I'm not quite
sure about organic oxidations with hydrogen peroxide though.
It\'s better to be pissed off than to be pissed on.
|
|
|
Sandmeyer
National Hazard
Posts: 784
Registered: 9-1-2005
Location: Internet
Member Is Offline
Mood: abbastanza bene
|
|
I would try to separate the aldehyde from ketone by bisulfite adduct, aldehydes react much faster. Check the vogel's for method.
EDIT: this might be of interest http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organisc...
[Edited on 7-4-2006 by Sandmeyer]
|
|
|
brainetix
Harmless
Posts: 4
Registered: 6-4-2006
Member Is Offline
Mood: No Mood
|
|
Thanx for the answers!
Will the aldehyde also form an addition product with NaI?
With ketones it will (Vogel´s 5th, p. 408). Maybe not with aldehydes?
[Bearbeitet am 7-4-2006 von brainetix]
|
|
|
leu
Hazard to Others
Posts: 368
Registered: 13-10-2005
Member Is Offline
Mood: No Mood
|
|
From:
http://www.erowid.org/archive/rhodium/chemistry/p2p.phenylac...
Known clandestine samples of P2P synthesized by Route 1A or 1B which contained an abundance of components were examined by instrumental methods
and also subjected to classical isolation techniques. Chemical separations were conducted by means of a bisulfite addition complex and Girard's
reagent T. The aqueous sodium bisulfate extraction of the reaction mixtures removed most of the P2P present; however, higher ketones do not produce
bisulfite adducts as easily because of the sensitivity of the additions to steric hindrance. The water-soluble bisulfite-P2P addition product may be
hydrolyzed with strong acid or base to regenerate P2P for examination. The nonbisulfite retained compounds were reacted with Girard's reagent T, a
material known to react with ketones to also form water-soluble adducts, which allows separation of ketonic and nonketonic compounds. An organic
extraction allowed clean isolation of all nonketonic compounds into an organic phase. These ketonic and nonketonic compounds were they. examined by
GC-FTIR-EIMS.
[Edited on 7-4-2006 by leu]
Chemistry is our Covalent Bond
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
