brainetix - 6-4-2006 at 09:18
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 - 6-4-2006 at 09:47
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.
Sandmeyer - 6-4-2006 at 09:52
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 - 6-4-2006 at 16:07
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 - 6-4-2006 at 16:50
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]