Structurally diverse new series of 5H-[1,2,4]triazolo[3,4b] [1,3,4]thiadiazine heterocycles having medicinally privileged nucleus have been synthesized by simple and solvent free environmental benign methods. A mixture of 4-amino-5-substituted-1,2,4-triazolo-3-thiol and β-diketone/ β-ketoester and catalytic amount of hydrazine hydrate exposed to microwave irradiation in microwave oven. The intermediate 4-amino-1,2,4-triazole-3-thiols were also synthesized by entirely new solvent free environmental friendly methods. The synthesized target compounds (4a-o) were characterized by elemental analysis as well as spectral studies and screened for antimicrobial activities.
1,2,4-Triazole, 1,4-Thiazine, 1,3,4-Thiadiazine, Biodynamic nucleus, β-Ketoester, Irradiation, Antimicrobial, Microwave.