The change in the electronic nature of benzoic acid followed the proposed reaction mechanism. The key C-O bond formation occurs between the carboxylate anion and oxonium cation, and the nucleophilicity of carboxylate directly influenced the efficiency. Electronwithdrawing substitutions at the para position reduced reactivity. and 36% (PEO 20K, 2i-20k), respectively. Conversely, the electron-deficient 2-pyridine carboxylic acid (1j) displayed good efficiency at 62% (2j-6k) and 68% (2j-20k), respectively.