Synthesis and antitumor activities of 1, 2-benzothiazines［1, 3, 4］thiadiazolo［3, 2-a］［1, 3, 5］triazin derivatives

Based on the drug design principle of reactive functional group splicing, nine novel title compounds were designed and synthesized with piroxicam intermediate as the starting material. Their structures were characterized by ¹H NMR and MS analysis. The in vitro antitumor activity evaluation suggested that compounds 6f , 6h and 6g exhibited good inhibitory reactivity on pancreatic cancer cell line Capan-1(IC₅₀=2. 4±0. 5 μmol/L), leukemia cell line L1210(IC₅₀=5. 4±0. 2 μmol/L), and human liver cancer cell line SMMC-7721(IC₅₀=3. 8±0. 2 μmol/L), respectively. The introduction of thiadiazolo［3, 2-a］triazine side chain could improve the antitumor activity of these compounds.