Making α-Bromo Carboxylic Acids

The Hell–Volhard–Zelinski reaction makes α-brominated carboxylic acids. It uses a mixture of phosphorus tribromide and bromine. This method is a standard way to add bromine at the alpha position of a carboxylic acid.

Phosphorus tribromide can be used directly in the reaction. It can also be forme...

Hell–Volhard–Zelinsky reaction is a method to convert carboxylic acids bearing α hydrogen to α-brominated carboxylic acids in the presence of a mixture of phosphorus tribromide and bromine, followed by hydrolysis.

Phosphorus tribromide acts as a catalyst—it is either added directly or generated in situ by the reaction of red phos...