A facile synthesis of 6,7-di-[substituted]-phenyl-3-pyridin-4-yl-5H-[1,2,4]-triazolo-[3,4-b]-[1,3,4]-thiadiazines have been carried out by reacting 4-amino-3-mercapto-5-pyridin-4-yl-4H-[1,2,4]-triazole with substituted benzoins in presence of potassium hydroxide. The required 4-amino-3-mercapto-5-pyridin-4-yl-4H-[1,2,4]-triazole was synthesized by reacting isoniazide with carbon-disulphide and potassium hydroxide followed by the addition of hydrazine hydrate. The acetylation of triazolo-thiadiazines afforded monoacetyl derivatives. The constitution of synthesized compounds have been delineated on the basis of chemical transformation, elemental analysis, equivalent weight determination and IR, 1H NMR spectral studies. The title compounds have been assayed for their biological activity against gram-positive as well as gram-negative microorgansms.
Synthesis, Biological activity, Triazolo-thiadiazines