The present invention relates to a method of preparing a phenoxy alkanoic, alkenoic, or alkynoic acid or a salt thereof from a phenoxy containing compound via a dicarboxylate intermediate. The phenoxy alkanoic, alkenoic, and alkynoic acids and salts thereof prepared by this method are suitable for use in composition for delivering active agents via oral or other routes of administration to animals. Furthermore, the present invention relates to phenoxy dicarboxylic acids and their salts for delivering active agents, such as biologically or chemically active agents, to a target.