Acid-Catalyzed, Silica-Supported, One-Pot Benzoylation Route to Synthesize 2-(Substituted Phenyl)oxazolo[4,5-b]pyridines Under Ambient Conditions

The present paper describes a silica-supported, perchloric-acid-catalyzed, efficient protocol for the synthesis of 2-(phenyl)oxazolo[4,5-b]pyridine derivatives. This strategy has high conversion, simple workup procedures, ambient conditions, short reaction times, and a reusable catalyst. Structures of the synthesized compounds have been established on the basis of elemental analysis and spectral data (IR, ¹H NMR, ¹³C NMR, and mass spectrometry). Moreover, to investigate the mechanistic details of the reaction and to ascertain the regioselective outcome of the product, local nucleophilicity descriptors N_k at B3LYP/6-311G++(d, p) level were determined and analyzed.