COOH + PBr3

[BiomajorPreDent]

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Quick question!!

I know that if COOH reacts with SOCl2 or PCl3 you get an acid chloride.

but if a COOH reacts with a Br3 do you get an acid bromide? or do you get the Hell-Volhard-Zelinski reaction?

How do you tell?

I assume you always get just the HVZ rxn because I cant even find the acyl bromide in my textbook....(except as an intermediate in the HVZ reaction) 😕

 

[joonkimdds]

I think PBr3 is same as PCl3 except it's Br.

 

[nze82]

If you use PBr3 you will end up with acid bromide. Hell-Volhard-Zelenski will only occur if you use Br2, along with a P catalyst and H2O. Also, for Hell-Volhard-Zelenski to occur, an Alpha Hydrogen must be present!

 

[elowdds]

Depending if you have an alpha C, then you will get HVZ. That is according to wiki link http://en.wikipedia.org/wiki/Hell-Volhard-Zelinsky_halogenation.