A Facile, Efficient and Convenient One Pot Synthesis of Benzoxazoles from 1,2-diols and 2-aminophenols with Pb(OAc)4 Reagent

Background: In this work, a series of benzoxazole derivatives has been synthesized using 1,2-diols and 2-aminophenols in the presence of lead tetraacetate. This one pot cyclocondensation involves the breaking of a C-C bond and formation of C-O and C-N bonds in a single synthetic operation. Methods: The synthesis of benzoxazole derivatives is developed through the reaction of 1,2-diols and 2-aminophenols in the presence of lead tetraacetate in ethanol under reflux conditions. Results: A series of benzoxazole derivatives was synthesized in good yields (82-96%) under reflux for 2-3.5 hours in ethanol solvent. The structural assignments of these compounds were made on the basis of elemental analysis and spectroscopic data. Conclusion: This domino reaction implies oxidation, condensation, cyclization and dehydrogenation. This procedure is an alternative to the existing procedures for the synthesis of these compounds.