Synthesis of 6‑amino‑2‑oxo‑ 4‑aryl‑4H‑1,3‑dithiine‑5‑carbonitrile derivatives by reaction of benzohydrazide, carbondisulfide and 2-benzylidenemalononitriles

The development of simple, versatile, and environmentally friendly processes or methodologies forwidelyused organic compounds from readily available reagents is one of the major challenges for chemists in organic synthesis [1]. Organic sulfur compounds are widespread in numerous natural products and widely used as various artificial chemicals. These compounds are found in many products of biological and medical [2] relevance as well as in commercial drugs [3]. The mixture of benzohydrazide 1, carbondisulfide in acetonitrile (7 ml) was stirred for 30 min and then 2-benzylidenemalononitrile 2 was added, and the mixture was stirred for 24 h. After completion of the reaction, determined by TLC, the solvent was removed under reduced pressure, and the viscous residue was purified by column chromatography (Merck 230–400 mesh) using n-hexane-EtOAc (2:1) as eluent to give 6-amino-2-oxo- 4-aryl-4H-1,3-dithiine-5- carbonitrile 3. The structure of these products were proved by 1H-NMR, 13C-NMR and IR spectral data( Figure 1).