Heterocyclic systems containing bridgehead nitrogen atom: Synthesis and evaluation of biological activity of imidazo[2,1-b]-1,3,4-thiadiazolo [2,3-c]-s-triazoles, s-Triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b] quinoxaline and bis-(s-Triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b][imidazo[4,5-b]- cyclohexane]-5a,6a-diene)

Abstract

Condensation of 4-amino-5-mercapto-3-(α-naphthyl)-s-triazole (1) with cyanogen bromide gives 6-amino-3-(α-naphthyl)-s-triazolo[3,4-b]-1,3,4- thiadiazole (2) which on condensation with chloranil yields 3,9-di-(α- naphthyl)-6,14- dioxo-bis-(s-triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4, 5-b]cyclohexane]-5a,6a-diene) (3). 3-(α-naphthyl)- s-triazolo[3,4-b]-1,3, 4-thiadiazolo[3,2-b]imidazo[4,5-b]quinoxaline (4) is obtained by a similar condensation of (2) with 2,3-dichloroquinoxaline. The reaction of (2) with a-haloketones followed by bromination affords 7-aryl-3-(α- naphthyl)-imidazo[2,1-b]-1,3,4-thiadiazolo[2,3-c]-s-triazoles (5) and their 6-bromo analogues 6 respectively. The structures of all newly synthesized compounds were established on the basis of elemental analyses, IR, 1H-NMR. The antibacterial and antifungal activities of all newly synthesized compounds have also been evaluated.