I have a water soluble polymer (Mw ~ 9000 g/mol; No. of monomers ~ 45) with a bromine atom at one end of the chain. I want to convert this Br-group to -COOH group. The Br is attached to an secondary aliphatic carbon, i.e. this carbon has one H-atom. Since the polymer is water soluble, hence it would be preferable to carry out the conversion in water or any other solvent where the reaction can happen would be fine, such as heterogeneous system. I have been thinking various ways but could not decide. Any help would be highly appreciable. Thank you.