SpicyBrown (Hive Bee)
04-23-02 19:25
No 300477
      Brominating 2CH: Freebase or HCl salt?  Bookmark   

Fellow bees,
SWIM has a dream of brominating 2CH using elemental bromine dissolved in glacial acetic acid. If one was to start with 2CH HCl, can this be brominated as-is?
SWIM searched The Hive extensively, and Post 28888 (zooligan: "Re: 2cb For the Chemistry Impared", Newbee Forum) by Zooligan is the only mention of brominating the HCl salt. All other refs SWIM has seen brominate the freebase of 2CH. So, must the 2CH be converted into it's freebase prior to brominating? If not, is there any known yield benefit from using the freebase over the acid salt?

Thanks-
SpicyBrown
 
 
 
 
    hest
(Hive Bee)
04-23-02 19:51
No 300487
      Iff the HCl salt is soluble in the AcOH (I don't ...  Bookmark   

Iff the HCl salt is soluble in the AcOH (I don't think it is, the HBr of 2-cb is not) then it's posible, but why bother, the Shulgin way works greath. Iff you want to play, try to substitute the bromine and AcOH with something else (NBS and MeCN ??)
 
 
 
 
    SpicyBrown
(Hive Bee)
04-23-02 20:12
No 300496
      Re: Iff the HCl salt is soluble in the AcOH (I ...  Bookmark   


Iff the HCl salt is soluble in the AcOH (I don't think it is, the HBr of 2-cb is not) then it's posible,




Is there any reason why the 2CH couldn't be dissolved in a minimal amount of H2O and added to the HOAc/Br2? SWIM understands that the 2CB HBr is soluble in H2O and won't crystalize upon formation, but is there any reason why the post-rxn mixture couldn't be washed with DCM to remove excess bromine and then acid/based as usual? Perhaps the only drawback being extra NaOH needed to neutralize the HOAc.


but why bother, the Shulgin way works greath.




SWIM has no doubt that it does, but in these dreams the 2CH is already in the HCl salt form (it had to be stored for an extended period of time, forming the HCl salt seemed the most convienient way for this). If basifying/extracting/removing solvent pior to brominating can be skipped, that would be nice.

SpicyBrown

 
 
 
 
    yellium
(Hive Addict)
04-23-02 21:15
No 300504
      When you do A/B extractions, remember to increase ...  Bookmark   

When you do A/B extractions, remember to increase the polarity of the water by adding lots of salt to it. See also thread `MDMA the phase transfer catalyst'. 
 
 
 
 
    SpicyBrown
(Hive Bee)
04-24-02 12:10
No 300754
      Another question would be, does anybody know if ...  Bookmark   

Another question would be, does anybody know if water can interfere with the bromination?

SWIM will probably just convert the HCl salt into the freebase anyway, might as well follow the established procedures. :)

SpicyBrown
 
 
 
 
    hest
(Hive Bee)
04-24-02 13:38
No 300769
      wather  Bookmark   

Some wather (<1%) won't doo anny harm. But try to do it as dry as posible.