Inorganic base-catalyzed formation of antivirally active <it>N</it>-substituted benzamides from α-amido sulfones and <it>N</it>-nucleophile

• Main Authors: Wang Zhenchao, Bhadury Pinaki S, Li Xiangyang, Hu Deyu, Song Baoan, Jin Yi, Yang Song
• Format: Article
• Language: English
• Published: BMC 2011-05-01
• Series: Chemistry Central Journal
• Online Access: http://journal.chemistrycentral.com/content/5/1/21

<p>Abstract</p> <p>Background</p> <p>Heteronucleophiles as well as carbanionic reagents can be used to react with α-amido sulfones, thus giving the opportunity to prepare a large array of amino derivatives. Since, novel 1,3,4-oxadiazole-2-thiol derivatives can serve as potent nucleophiles, we employed 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the nucleophilic source of nitrogen in the reaction with α-amido sulfones.</p> <p>Results</p> <p>A series of <it>N</it>-substituted benzamides bearing 1,3,4-oxadiazol unit were prepared for the first time by the reaction of <it>in situ </it>generated protected imine from α-amido sulfones with 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the source of nitrogen nucleophile. Some of the synthesized products displayed favourable antiviral activity against <it>cucumber mosaic virus </it>(CMV) in preliminary antiviral activity tests. The title compounds <b>5c</b>, <b>5o </b>and <b>5r </b>revealed curative activity of 42.2%, 48.7% and 40.5%, respectively against CMV (inhibitory rate) compared to the commercial standard Ningnanmycin (53.4%) at 500 μg/mL.</p> <p>Conclusion</p> <p>A practical synthetic route to <it>N</it>-benzoyl-α-amido sulfones by the reaction of 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the source of nitrogen nucleophiles with <it>in situ </it>generated protected imine from <it>N</it>-benzoyl-α-amido sulfones is presented. The reaction catalyzed by an inorganic base has considerable significance to exploit the potential of α-amido sulfones in organic synthesis.</p>