Application of 3‐methylthiopyrido[4,3‐ e ]‐1,4,2‐dithiazine 1,1‐dioxide to the synthesis of novel series of 4 H ‐pyrido[4,3‐ e ]‐1,2,4‐thiadiazine derivatives with potential biological activity

Two series of 4 H ‐pyrido[4,3‐ e ]‐1,2,4‐thiadiazine derivatives 3 , 4 , 5 and 7 , 8 , 9 , 10 , 11 , 12 were synthesized by the reactions of 3‐methylthiopyrido[4,3‐ e ]‐1,4,2‐dithiazine 1,1‐dioxide 1 with 2‐or 6‐hydrazinoazines and 2‐aminophenols or 2‐aminothiophenol, respectively. Aminolysis of 8 (R = Me, Y = O) afforded the corresponding 3‐(R‐amino)‐4‐(2‐hydroxy‐5‐methylphenyl)‐4 H ‐pyrido[4,3‐ e ]‐1,2,4‐thiadiazine 1,1‐dioxides 13 , 14 , 15 , 16 , 17 , 18 . The structures of these compounds were confirmed on the basis of elemental analysis, spectral data, and X‐ray crystallography. Compounds 3 , 4 , 5 , 7 , 8 , 9 , 10 , 12 , 13 , 14 , 15 , and 17 , 18 were screened in vitro for antibacterial activity . Moreover, preliminary in vitro anticancer assay was performed for compounds 3 , 7 , 10 , 11 , 12 , 13 , and 17 , 18 at the National Cancer Institute (Bethesda, MD) at a single dose (10 μ M ) in the full NCI 60 cell panel. J. Heterocyclic Chem., (2009).