Synthesis and Antimicrobial Screening of Novel Bis-Triazolo-Thiadiazoles Containing Bridgehead Nitrogen

A facile synthesis of 1,4-bis-(6-arylimino-[1,2,4]-triazolo-(3,4-b)-[1,3,4]-thiadiazol-3-yl)-benzenes have been carried out by reacting 1,4-bis-(4-amino-3-mercapto-4H-[1,2,4]-triazol-5-yl-benzene with N-aryl isocyanodichlorides followed by the basification with dilute ammonium hydroxide solution. 1,4-bis-(4-amino-3-mercapto-4H-[1,2,4]-triazol-5-yl-benzene was synthesized by the interaction of terephthalic acid dihydrazide with carbondisulphide and potassium hydroxide followed by the addition of hydrazine hydrate. The acetylation of bis-triazolo-dithiadiazines afforded di-acetyl derivatives. The structures of synthesized compounds have been established on the basis of chemical transformation, elemental analysis, equivalent weight determination and IR, 1H-NMR, mass spectral studies. The title compounds have been assayed for their antimicrobial activity against gram-positive as well as gram-negative micro-organisms.