Experimental and theoretical approving of anomeric based oxidation in the preparation of 2-sbstituted benz-(imida, oxa and othia)-zoles using [2,6-DMPy-NO2]C(NO2)3 as a novel nano molten salt catalyst

Abstract

The synthesis of 2-sbstituted benz-(imida, oxa and othia)-zole derivatives were occurred in the presence of 2,6-dimethyl-1-nitropyridin-1-ium trinitromethanide [2,6-DMPy-NO₂]C(NO₂)₃ via the condensation reaction between 1,2-phenylenediamine or 2-aminophenol or 2-aminothiophenol and corresponding aldehyde at room temperature under solvent-free conditions respectively. [2,6-DMPy-NO₂]C(NO₂)₃ as a nano molten salt (NMS) catalyst was fully characterized by Fourier transform infrared (FT-IR), nuclear magnetic resonance (¹H NMR and ¹³C NMR), mass, thermal gravimetric (TG), derivative thermal gravimetric (DTG), X-ray diffraction patterns (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. The described reactions are in close agreement with the green chemistry disciplines and their major advantages are good yields, short reaction time and ease of separation. Our recently new introduced concept entitled “anomeric based oxidation” was proposed for the final step of the described synthesis and it was also approved using theoretical studies.