The Hive => Methods Discourse => Topic started by: kjb1891 on March 07, 2004, 08:08:00 PM
Title: 2CH Bromination
Post by: kjb1891 on March 07, 2004, 08:08:00 PM
So, SWIM has questions about doing bromination of 2,5-dimethoxy-PEA HCl into 2CB HBr. All you have to do is bring a solution of 2CH and GAA to a good stir. Then, add a solution of elemental bromine and GAA. Once it forms a brown crystaline mass and returned to room temps it can be cleaned up with acetic acid and ethyl acetate to give fairly good 2CB HBr. Is there anything else to it?
Title: ask the inventor
Post by: gsus on March 07, 2004, 08:18:00 PM
click on the PIHKAL link on the bottom of the page, then click on 2C-B.
Title: Bromine
Post by: wolfx on March 08, 2004, 08:54:00 AM
Just in case, you will need a fume hood or something like that, because of the very iritating and toxic bromine fumes.
Also, transfering the bromine with a pipette is difficult because it vaporizes and falls from the pippete.
There are alternative bromination procedures whithout using bromine. I have never tried any nor the bromine either, though. There is also a lot of posts, use TFSE.
Title: Prep of 2C-B.HBr
Post by: Rhodium on March 08, 2004, 10:59:00 AM
Title: Chilling the bromine would help reduce the...
Post by: kjb1891 on March 08, 2004, 11:26:00 AM
Chilling the bromine would help reduce the evaporation wouldn't it?
Title: Yes, that is also covered in the document I...
Post by: Rhodium on March 08, 2004, 11:32:00 AM
Yes, that is also covered in the document I linked.
Title: Would the acetic acid and ethyl acetate be...
Post by: kjb1891 on March 08, 2004, 01:40:00 PM
Would the acetic acid and ethyl acetate be sufficient enough for getting rid of impurities? Thanks for all the info
Title: getting rid of the impurities
Post by: Vaaguh on March 09, 2004, 06:09:00 AM
No this will not get rid of all the impurities, washing the compound afterwards with cold dry ether followed by a recrystallisation will remove most impurities.
Title: I meant to say washing with the acetic acid,...
Post by: kjb1891 on March 10, 2004, 11:54:00 AM
I meant to say washing with the acetic acid, but doing a recrystallization with the ethyl acetate as the solvent. Or is there a better solvent to use?
Title: cleanup
Post by: Vaaguh on March 11, 2004, 02:44:00 AM
A suggestion might bee washing with ethyl acetate followed by cold dry ether and for the recrystalisation either ether/methanol or ether/ipa.