Application of novel nanostructured dinitropyrazine molten salt catalyst for the synthesis of sulfanylpyridines via anomeric based oxidation

Abstract

1,4-Dinitropyrazine-1,4-diium trinitromethanide {[1,4-pyrazine-NO2][C(NO2)3]2} as a novel nanostructured molten salt (NMS) catalyzed the synthesis of 2-amino-3,5-dicarbonitrile-6-sulfanylpyridine derivatives via the one-pot three-component condensation reaction between several aromatic aldehyde, malononitrile and benzyl mercaptan at room temperature under solvent-free conditions. The synthesized NMS catalyst was fully characterized by FTIR, 1H NMR, 13CNMR, mass, thermal gravimetric, X-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy analysis. The major advantages of described methodology are mildness, ease of separation, good yields and short reaction times. A rational mechanism was suggested for the final step of the 2-amino-3,5-dicarbonitrile-6-sulfanylpyridines synthesis. We think that the proposed mechanism has potential for entering into the graduate text book in the future.