I am trying to find out how $\ce{POBr3}$ reacts with $\ce{-COOH}$ group (benzoic acid to be specific). I found that it performs an elimination reaction with alcohols to give alkenes. I have also seen that keto group was converted to $\ce{-Cl}$ using $\ce{POCl3}.$
But I don't think that $\ce{POCl3}$ will eliminate $\ce{-COOH}$ group — that seems like nonsense. Eliminating using $\ce{-OH}$ from $\ce{-COOH}$ would give me a carbon with five bonds. Exchanging the $\ce{=O}$ from $\ce{-COOH}$ would give me something I have never seen and it doesn't even look good…
So I am sort of out of ideas. I'd appreciate any hint what to do.