obituary (Hive Addict)
08-12-01 01:38
No 203572
      phenylacetic acid  Bookmark   

Baeyer-Villiger Rearrangement of a ketone to an ester.
well, the ketone can be anything along the lines of 1-phenyl-hexamethylbadass-2-one

as long as the phenyl is 1-position and the alkyl group has a carbonyl at the 2-position
yes- so take something like 1-phenyl-hexan-2-one  and peracid it
you get the respective esters and the acids---- so hydrolyze to get the acids
basify and extract with water    obit'll use NaCO3 in case it's sensitive to strong acids
re-acidify and bam- phenylacetic acid

obit thinks that max yeild for our acid would be 50%   b/c it doesn't say which side the ester forms on the ketone- so if it splits 50/50 on either side- then 50% would be the max possible amount

just a thought

 
 
 
 
    obituary
(Hive Addict)
08-13-01 00:41
No 203881
      Re: phenylacetic acid  Bookmark   

anybody?
 
 
 
 
    Rhodium
(Chief Bee)
08-13-01 01:19
No 203905
      Re: phenylacetic acid  Bookmark   

Yes, the reaction should work all right in theory, but I don't know about if the reaction would be selective for cleaving on one side or another of the carbonyl. Do you have any suggestions about what cheapish ketone to start with? We wouldn't want to start with P2P, would we?
 
 
 
 
    obituary
(Hive Addict)
08-13-01 05:14
No 203971
      Re: phenylacetic acid  Bookmark   

point is that the average P2something ketone isn't going to be watched and they can all be converted to P2P in theory.
and no, obit hasn't even approached working out the procedure.  wanted to run it by some others first. 
and if you're serious about the "start with P2P" question, then think about the cycle it would lock you into. 
the purpose is to create P2P from other ketones similar to it.
 
 
 
 
    Rhodium
(Chief Bee)
08-13-01 05:24
No 203976
      Re: phenylacetic acid  Bookmark   

I wasn't serious when saying you could start with P2P, but seriously I don't know of any cheap phenyl-2-ketones you could start your synthesis with. If you know any, please enlighten me.
 
 
 
 
    obituary
(Hive Addict)
08-13-01 05:26
No 203979
      Re: phenylacetic acid  Bookmark   

if obit finds some, will share. if not, then oh well.
what about oxidation of a 2-ol ? 
 
 
 
 
    Rhodium
(Chief Bee)
08-13-01 05:32
No 203983
      Re: phenylacetic acid  Bookmark   

That would also work, followed by a bayer-villiger oxidation.
 
 
 
 
    obituary
(Hive Addict)
08-13-01 05:37
No 203987
      Re: phenylacetic acid  Bookmark   

yes, but are the 2-ol's cheap enough?  readily avail?  shoot even a halo compound, swap with base to give OH, and then oxidize.  but only if the materials are cheap and readily avail.
 
 
 
 
    Rhodium
(Chief Bee)
08-13-01 05:47
No 203993
      Re: phenylacetic acid  Bookmark   

I would buy phenethylalcohol (it is not controlled), and oxidize its ass of to phenylacetic acid directly.
 
 
 
 
    obituary
(Hive Addict)
08-15-01 17:32
No 204785
      Re: phenylacetic acid  Bookmark   

http://www.pmf.ukim.edu.mk/PMF/Chemistry/reactions/baeyer-villiger.htm