Sciencemadness Discussion Board

Boron Tribromide

hkparker - 28-2-2011 at 22:52

Hey everyone.

So I'm looking into doing a video on the reaction between boron and bromine and I was wondering if someone could shed some light on the uses of its product, boron tribromide. I know some obvious stuff such as its properties and hydrolysis products but I was looking for some specific uses, perhaps in organic chemistry. Any information is helpful, thank you.

Hayden

smuv - 1-3-2011 at 00:29

Its great for cleaving ethers. I have only used it for aromatic ethers, just take 1 eq BBr3 to ~2.5 eq aromatic alkyl ether and stir overnight in reasonably dry DCM. Quench with water, stir with dilute NaOH(aq) for a while (this helps decompose the borate ester which can take quite a while to hydrolyze under acidic conditions) separate the aqueous layer and acidify it. From there you can either filter your phenol (if a solid and insol in water) or you can go for recovery via extraction. The alkyl group is lost as the alkyl bromide btw.

I want to caution you about BBr3, it fumes very strongly in open air (worse than other things like SnCl4, maybe a bit worse than TiCl4).

[Edited on 3-1-2011 by smuv]

mr.crow - 1-3-2011 at 11:36

Have you seen this video?

hkparker - 1-3-2011 at 12:26

Wow, how did I miss that? That you mr.crow! I'm a big periodicvideos fan, I don't remember that one for some reason though...