Synthesis and Antioxidant Activity of Functionalized Pyridinyl-Methylthiosemicarbazide Derivatives.

A new series of 1-(6-amino-3,5-dicyano-4-(substituted)pyridin-2-yl)-4-methylthiosemicarbazide derivatives 4(a–i) was achieved by the reaction of malononitrile and 4-methyl-3-thiosemicarbazide with various aldehydes. All the newly designed compounds were structurally established by various analytical methods (IR, 1H, 13C NMR, and HRMS). Further, all the entitled derivatives were evaluated for their potential antioxidant activity by DPPH radical method in which standard, ascorbic acid, was used for comparison and results revealed that the derivatives, 4a and 4i exhibited the highest antioxidant effect. [ABSTRACT FROM AUTHOR]