2,2′-Biquinoline-4,4′-dicarboxylic acid dipotassium salt trihydrate is a biquinoline derivative. It is a biquinoline based water soluble ligand.It forms a water soluble palladium complex which allows aqueous aerobic oxidation of primary, secondary and benzylic alcohols. Since the reaction solvent is only water and the oxidant is air, it may be used as a green alternative to the traditional methods of oxidation. A biquinoline derivative that may be used as a green alternative to the traditional methods of oxidation.