psyx7 (Stranger)
01-07-04 06:52
No 480866
       Applications of NBS?     

I know that N-BS can bee used to brominate substituted benzenes, and apparently also amines. But there a couple of questions that I have been unable to find answers to despite using both TFSE and Google:

Can NBS be used to selectively brominate aldehydes and ketones, e.g. 2,5-DMP2P __> 4-Br-2,5-DMP2P or 2,5-DMB __> 4-Br-2,5-DMB?

I have a feeling that the answer is probably no since I have been unable to find any references to it, but thought I'd check with the experts first laugh

TIA,
psyx 		 
 
 
 
    hest
(Hive Adickt)
01-07-04 10:12
No 480883
       NBS     

Bromination of the aromatic core with NBS in the dark works greath, use DCM or Acetonitrile as solvent, red this [ url ] ../rhodium /2cbde.html [ /url ] 		 
 
 
 
    Nicodem
(Hive Bee)
01-07-04 11:45
No 480893
       I don't think it would work for 2,5-DMP2P...     

I don't think it would work for
2,5-DMP2P -> 4-Br-2,5-DMP2P
because of the ketone group.
Even though NBS does not produce Br2 it does produce free radicals and slowly also some electrophilic Br+ (in dark) and these react readily with the alpha-hydrogens of ketones like 2,5-DMP2P (producing some just some useless 'tear-gas' compounds).
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